9专项训练3
三年级数学思维专项训练9--年龄问题(原卷+解析版)
三年级思维训练9--年龄问题1．今年弟弟6岁，哥哥15岁，两人的年龄和为65岁时，哥哥--------岁，弟弟-------岁。
2．三个人的年龄和是75岁，最大的人比其他两人的年龄和还要大15岁，最小的人是12岁，问三个人的年龄和各是多少？3．王强、李刚是哥哥，小丽小红是妹妹，四人的年龄和是90岁，哥哥都比妹妹大4岁，小红比王强小5岁，小红---------岁。
4．小胖比他的表姐小12岁，再过4年小胖的年龄是他表姐的一半，他俩今年的年龄和是------岁。
5．一位妇人，人到中年，很不愿提起自己的年龄，但她又不愿意说谎，一天，有人问及她的年龄，她只好实话实说：“我4年后的年龄的6倍减去我3年前的年龄的6倍，就是我现在的年龄”这位妇人今年-----岁。
6．祖父今年75岁，三个孙子的年龄分别是17、15和13岁，多少年后三个孙子的年龄和等于祖父的年龄？7．小敏爸爸、爷爷的年龄加起来是100岁，又知道爷爷过的年数小敏的月数一样多；爸爸年龄比小敏年龄多6倍，今年小敏------岁，爸爸---------岁，爷爷-------岁。
8．小丽与父母今年的年龄和是87岁，爸爸比妈妈大6岁，几年前，爸爸的年龄是小丽年龄的11倍，妈妈的年龄是小丽年龄的9倍。
小丽今年--------岁。
9．摩比、大宽、金儿的年龄为3个连续的自然数，摩比年龄最大。
今年他们三人与博士的年龄之和为100岁。
17年后，他们三人的年龄和恰好等于博士的年龄。
那么，今年摩比---------岁。
10．爷爷和孙子今年的年龄和不足90岁，爷爷的年龄是孙子的7倍；若干年后，爷爷的年龄是孙子的6倍，再过若干年后，爷爷的年龄是孙子的5倍。
那么今年爷爷是-------岁。
11．晶晶的岁数是父亲的一半，父亲的岁数则是玲玲的3倍，他们三个人岁数之和刚好是88岁祖母的年龄。
那么晶晶是-------岁，玲玲是---------岁。
12．甲对乙说：“当我的岁数是你现在的岁数时，你才5岁。
初中语文阅读理解专项训练附答案-9
初中语文阅读理解专项训练附答案9阅读理解历来是学生考试的一大失分点，通过针对训练,多读、多做、多反思、多总结，是可以提高解题能力，本系列通过文言文、现代文两大部分，为一线优秀教师、学生提供参考，大家一定会获益匪浅.一、诚实是一种可贵的品质①2002年6月，一家知名电视台的记者对世界著名实验物理学家丁肇中先生进行专访.记者问：“我感觉您每一个人生阶段都有明确的选择……一个人怎么能够每一次选择都这么坚定和正确呢?”丁肇中回答：“我不知道。
可能比较侥幸吧！"记者又追问：“在这里面没有必然吗？"丁肇中依然回答:“我不知道.”记者还是不甘心：“怎么能让自己今天的选择，日后想起来不后悔？”丁肇中依然回答：“我不知道.因为我还没有后悔过,所以我真的不知道。
”记者无奈:“我发现咱们谈话过程中，您说的最多的一句话就是‘我不知道’。
”丁肇中这次作了肯定回答：“是！确实这是事实。
不知道的，我绝对不能说知道。
”②我相信，每一个听说过这个故事的人，都会被丁肇中草药先生的诚实所打动。
在这个世界上，诚实是一束阳光，能照亮一个人的心灵；诚实是一座桥梁，能沟通人与人之间的情感；诚实是_________________________,能_________________________。
③诚实是一种可贵的品质，它的魅力在于不说假话、大话，以诚待人，以心感人。
诚实不需要华丽的词藻来修饰，不需要甜言蜜语来遮掩，它是生命的原汁原味，它是天地之间的一种本真和自然.④1986年，美国心理学家安德森曾做过一个耐人寻味的调查，他将550个描写人的形容词列成一张表，让大学生们从中选择自己最喜欢的品质和最厌恶的德行。
结果显示,评价最高的品质是“真诚”，最厌恶的确良德行是“撒谎”、“虚伪”、“不老实”。
⑤如今有些人，总是特别害怕别人说自己不深刻，因此总是千方百计地伪装自己、表演自己。
固然，人生是个大舞台，我们都是表演者，但是，一位真正优秀的演员,不是仅仅依靠外表的华丽取悦观众，而是凭借内心世界的真诚、丰富来赢得更多的掌声。
北师大版数学3年级上册 第9单元(除法)基础训练4(含答案)
北师大版二年级上册数学第九单元除法基础训练一.选择题1.把一些球每盒装6个，正好分完，这些球可能有（）个。
A.24B.28C.322.下面的算式中，不一定等于0的算式是（）。
A.0+△B.0÷△C.0×△3.有两个数的积是72，差是1，这两个数是（）。
A.6和7B.7和8C.8和94.48连续减6，得出0需要减几次? （）A.6次B.8次C.3次5.下面各数除以9没有余数的是（）。
A.42B.45C.56二.判断题1.从81里连续减9，要求几次减完，列式为81÷9。
（）2.笔算除法时，每次除得的余数都要比除数小。
（）3.计算算式28÷7和28÷4时用同一句口诀。
（）4.21可以被7整除。
（）5.计算算式28÷7和28÷4时用同一句口诀。
（）三.填空题1.36里面有（）个6，（）个9。
2.小丁丁和20个同学在森林公园走“勇敢者之路”，每7个人一组，可编________组？3.有21根小棒，每3根摆一个△，可以据（）个△。
4.计算7×8、8×7、56÷7和56÷8时,都可以用________这句乘法口诀来解答。
5.用容积6毫升的小瓶装48毫升的药水，共需要小瓶________个。
四.计算题1.直接写出结果。
7×3= 27÷3= 30÷5= 6×7=18÷3= 16-9= 9÷9= 36÷6=49÷7= 54÷6= 35+5= 48÷8=91-20= 40+7= 10÷2= 9×6=2.列式计算：（1）27里面有几个3？（2）除数是4，被除数是24，商是多少？（3）把30平均分成6份，每份是多少？五.解答题1.解答题。
（1）小明一个星期练21行字，平均每天练多少行字？（2）56个桃子平均分给7只小猴，每只小猴分到几个桃子？2.小华读一本81页的故事书，4天读了36页，照这样的速度，小华一共几天可以读完整本书？3.丽丽和红红比赛写毛笔字，丽丽3分钟写了27个，红红5分钟写了35个，请算一算谁写得比较快?4.36人玩老鹰捉小鸡游戏。
微专题：图形的旋转选择题专项——2021年九年级中考数学分类专题提分训练：(三)
如果别人思考数学的真理像我一样深入持久，他也会找到我的发现。
——高斯微专题：图形的旋转选择题专项——2021年中考数学分类专题提分训练：（三）1．如图，在△ABC中，AB＝AC，将线段BC绕点B逆时针旋转60°得到线段BD，∠BCE＝150°，∠ABE＝60°，连接DE，若∠DEC＝45°，则∠BAC的度数为．2．如图，把△ABC绕着点A顺时针方向旋转角度α（0°＜α＜90°），得到△AB'C'，若B'，C，C'三点在同一条直线上，∠B'CB＝46°，则α的度数是．3．已知：如图，△ABC中，∠C＝90°，AB＝3，BC＝2，将△ABC绕A点按顺时针旋转60°，得到△AB'C′，则CC′＝．4．如图，直角坐标系中，已知点A（﹣3，0），B（0，4），将△AOB连续作旋转变换，依次得到三角形①，②，③，④，…则第19个三角形中顶点A的坐标是．5．如图，将△ABC绕点A逆时针旋转一定的角度后，得到△ADE，且点B的对应点D恰好落在BC边上，若∠B＝70°，则∠CAE的度数是度．6．如图，在平面直角坐标系中，将边长为1的正方形OABC绕点O顺时针旋转45°后得到正方形OA1B1C1，依此方式，绕点O连续旋转2019次得到正方形OA2019B2019C2019，那么点A2019的坐标是．7．如图，在矩形ABCD中，AB＝3，AD＝4，将矩形ABCD绕着点B顺时针旋转后得到矩形A'BC'D'，点A的对应点A'在对角线AC上，点C、D分别与点C'、D'对应，A′D'与边BC交于点E，那么BE的长是．8．如图，线段AB＝4，M为AB的中点，动点P到点M的距离是1，连接PB，线段PB绕点P逆时针旋转90°得到线段PC，连接AC，则线段AC长度的最大值是．9．如图，在Rt△ABC中，∠ACB＝90°，将△ABC绕顶点C逆时针旋转得到△A′B′C，M 是BC的中点，P是A′B′的中点，连接PM，若BC＝2，∠BAC＝30°，则线段PM的最大值是．10．将点A（2，0）绕着原点按逆时针方向旋转135°得到点B，则点B的坐标为．11．如图，正方形ABCD的边长为1，P为AB上的点，Q为AD上的点，且△APQ的周长为2，则∠PCQ＝度．12．如图，把△ABC绕C点顺时针旋转35°，得到△A′B′C，A′B′交AC于点D，若∠A′DC＝90°，则∠A＝°．13．如图，将△AOB绕点O按逆时针方向旋转45°后得到△A′OB′，若∠AOB＝15°，则∠AOB′的度数是．14．如图，四边形ABCD的∠BAD＝∠C＝90°，AB＝AD，AE⊥BC于E，△ABE绕着点A旋转后能与△ADF重合，若AF＝5cm，则四边形ABCD的面积为．15．如图，在Rt△ABC中，∠BAC＝90°，AB＝2．将△ABC绕点A按顺时针方向旋转至△AB1C1的位置，点B1恰好落在边BC的中点处，则CC1的长为．16．如图，将△ABC的绕点A顺时针旋转得到△AED，点D正好落在BC边上．已知∠C＝80°，则∠EAB＝°．17．如图，在Rt△ABC中，∠BAC＝90°，∠B＝60°，△AB′C′可以由△ABC绕点A顺时针旋转90°得到（点B′与点B是对应点，点C′与点C是对应点），连接CC′，则∠CC′B′的度数是．18．如图，P是正三角形ABC内的一点，且PA＝6，PB＝8，PC＝10．若将△PAC绕点A逆时针旋转60°后，得到△P′AB，则点P与P′之间的距离为，∠APB＝．19．已知A，B，O三点不共线，点A，Aʹ关于点O对称，点B，Bʹ关于点O对称，那么线段AB 与A ʹB ʹ的关系是 ．20．如图，Rt △ABC 中，∠C ＝90°，AB ＝5，AC ＝3，现将△ABC 绕着顶点B 旋转，记点C 的对应点为点C 1，当点A ，B ，C 1三点共线时，求∠BC 1C 的正切值＝ ．21．在平面直角坐标系中，点A （﹣1，1），将线段OA （O 为坐标原点）绕点O 逆时针旋转135°得线段OB ，则点B 的坐标是 ．22．图1和图2中所有的小正方形都全等，将图1的正方形放在图2中①②③④的某一位置，使它与原来7个小正方形组成的图形是中心对称图形，这个位置是 ．23．将点（0，1）绕原点顺时针旋转90°，所得的点的坐标为 ．24．如图，将矩形ABCD 绕点A 旋转至矩形AB ′C ′D ′位置，此时AC ′的中点恰好与D 点重合，AB ′交CD 于点E ．若AB ＝3，则△AEC 的面积为 ．25．如图，在平面直角坐标系中，矩形OABC 的顶点B 坐标为（8，4），将矩形OABC 绕点O 逆时针旋转，使点B 落在y 轴上的点B ′处，得到矩形OA ′B ′C ′，OA ′与BC 相交于点D ，则经过点D 的反比例函数解析式是 ．参考答案1．解：连接AD，∵线段BC绕B逆时针旋转60°得到线段BD，则BC＝BD，∠DBC＝60°，∴△BCD为等边三角形，∴BD＝CD，∠DCB＝∠DBC＝60°，在△ABD与△ACD中，∴△ABD≌△ACD（SSS），∴∠ABD＝∠ACD，∵∠BCE＝150°，∴∠DCE＝90°，∵∠DEC＝45°，∴∠CDE＝∠DEC＝45°，∴CD＝CE＝CB，且∠BCE＝150°，∴∠CBE＝∠CEB＝15°，∵∠ABE＝∠DBC＝60°∴∠ABD＝∠ACD＝∠CBE＝15°，∴∠ABC＝∠ACB＝75°，∴∠BAC＝180°﹣∠ABC﹣∠ACB＝30°，故答案为：30°．2．解：由题意可得：AC＝AC′，∠C'＝∠ACB，∴∠ACC'＝∠C'，∵把△ABC绕着点A顺时针方向旋转α，得到△AB′C′，点C刚好落在边B′C′上，∴∠B'CB+∠ACB＝∠C'+∠CAC′，∠B'CB＝∠CAC'＝46°．故答案为：46°．3．解：连接CC′，如图所示．由旋转，可知：AC＝AC′，∠CAC′＝60°，∴△ACC′为等边三角形，∴CC′＝AC．在Rt△ABC中，∠C＝90°，AB＝3，BC＝2，∴AC＝＝，∴CC′＝．故答案为：．4．解：∵A（﹣3，0），B（0，4），∴OA＝3，OB＝4，∴AB＝＝5，∵△AOB连续作三次旋转变换回到原来的状态，而19＝3×6+1，∴第19个三角形的状态与第1个一样，∴第19个三角形中顶点A的横坐标为6×12＝72，纵坐标是4，即第19个三角形中顶点A的坐标是（72，3）．故答案为（72，3）．5．解：∵将△ABC绕点A逆时针旋转一定的角度后，得到△ADE，∴AB＝AD，∠BAD＝∠CAE，∴∠B＝∠ADB＝70°，∴∠BAD＝40°＝∠CAE，故答案为：40．6．解：∵四边形OABC是正方形，且OA＝1，∴A（0，1），∵将正方形OABC绕点O逆时针旋转45°后得到正方形OA1B1C1，∴A1（，），A2（1，0），A3（，﹣），…，发现是8次一循环，所以2019÷8＝252……3，∴点A2019的坐标为（，﹣）．故答案为（，﹣）．7．解：如图，过点B作BF⊥AC，过点E作EH⊥AC，∵AB＝3，AD＝4，∠ABC＝90°，∴AC＝＝＝5，∵S△ABC＝AB×BC＝AC×BF，∴3×4＝5BF，∴BF＝∴AF＝＝＝，∵将矩形ABCD绕着点B顺时针旋转后得到矩形A'BC'D'，∴AB＝BA'，∠BAD＝∠BA'D'＝90°，且BF⊥AC，∴∠BAC＝∠BA'A，AF＝A'F＝，∠BA'A+∠EA'C＝90°，∴A'C＝AC﹣AA'＝，∵∠BA'A+∠EA'C＝90°，∠BAA'+∠ACB＝90°，∴∠ACB＝∠EA'C，∴A'E＝EC，且EH⊥AC，∴A'H＝HC＝A'C＝，∵∠ACB＝∠ECH，∠ABC＝∠EHC＝90°，∴△EHC∽△ABC，∴∴∴EC＝，∴BE＝BC﹣EC＝4﹣＝，故答案为：．8．解：如图所示：过点C作CD⊥y轴，垂足为D，过点P作PE⊥DC，垂足为E，延长EP交x轴于点F．∵AB＝4，M为AB的中点，∴A（﹣2，0），B（2，0）．设点P的坐标为（x，y），则x2+y2＝1．∵∠EPC+∠BPF＝90°，∠EPC+∠ECP＝90°，∴∠ECP＝∠FPB．由旋转的性质可知：PC＝PB．在△ECP和△FPB中，，∴△ECP≌△FPB．∴EC＝PF＝y，FB＝EP＝2﹣x．∴C（x+y，y+2﹣x）．∵AB＝4，M为AB的中点，∴AC＝＝．∵x2+y2＝1，∴AC＝．∵﹣1≤y≤1，∴当y＝1时，AC有最大值，AC的最大值为＝3．故答案为：3．9．解：如图连接PC．在Rt△ABC中，∵∠A＝30°，BC＝2，∴AB＝4，根据旋转不变性可知，A′B′＝AB＝4，∴A′P＝PB′，∴PC＝A′B′＝2，∵CM＝BM＝1，又∵PM≤PC+CM，即PM≤3，∴PM的最大值为3（此时P、C、M共线）．故答案为：3．10．解：过B作BH⊥x轴于H，如图，∵点A的坐标为（2，0），∴OA＝2，∵点A绕着原点按逆时针方向旋转135°得到点B，∴OB＝OA＝2，∠AOB＝135°，∴∠BOH＝45°，∴△OBH为等腰直角三角形，∴BH＝OH＝×2＝2，∴B（﹣2，2）．故答案为（﹣2，2）．11．解：把Rt△CBP绕C顺时针旋转90°，得到Rt△CDE，如图，则E在AD的延长线上，并且CE＝CP，DE＝PB，∠ECP＝90°，∵△APQ的周长为2，∴QP＝2﹣AQ﹣AP，而正方形ABCD的边长为1，∴DE＝PB＝1﹣AP，DQ＝1﹣AQ，∴QE＝DE+DQ＝2﹣AQ﹣AP，∴QE＝QP，而CQ公共，∴△CQE≌△CQP，∴∠PCQ＝∠QCE，∴∠PCQ＝45°．故答案为：45．12．解：∵三角形△ABC绕着点C时针旋转35°，得到△AB′C′∴∠ACA′＝35°，∠A'DC＝90°∴∠A′＝55°，∵∠A的对应角是∠A′，即∠A＝∠A′，∴∠A＝55°；故答案为：55°．13．解：∵将△AOB绕点O按逆时针方向旋转45°后得到△A′OB′，∴∠A′OA＝45°，∠AOB＝∠A′OB′＝15°，∴∠AOB′＝∠A′OA﹣∠A′OB′＝45°﹣15°＝30°，故答案是：30°．14．解：∵AE⊥BC，∴∠AEB＝∠AEC＝90°，∵AB＝AD，△BEA旋转后能与△DFA重合，∴△ADF≌△ABE，∴∠AEB＝∠F，AE＝AF，∵∠C＝90°，∴∠AEC＝∠C＝∠F＝90°，∴四边形AECF是矩形，又∵AE＝AF，∴矩形AECF是正方形，∵AF＝5cm，∴四边形ABCD的面积＝四边形AECF的面积＝52＝25cm2．故答案为：25cm2．15．解：∵在Rt△ABC中，∠BAC＝90°，将该三角形绕点A按顺时针方向旋转到△AB1C1的位置，点B1恰好落在边BC的中点处，∴AB1＝BC，BB1＝B1C，AB＝AB1，∴BB1＝AB＝AB1，∴△ABB1是等边三角形，∴∠BAB1＝∠B＝60°，∴∠CAC1＝60°，∵将△ABC绕点A按顺时针方向旋转至△AB1C1的位置，∴CA＝C1A，∴△AC1C是等边三角形，∴CC1＝CA，∵AB＝2，∴CA＝2，∴CC1＝2．故答案为：2．16．解：∵△ABC的绕点A顺时针旋转得到△AED，∴AC＝AD，∠BAC＝∠EAD，∵点D正好落在BC边上，∴∠C＝∠ADC＝80°，∴∠CAD＝180°﹣2×80°＝20°，∵∠BAE＝∠EAD﹣∠BAD，∠CAD＝∠BAC﹣∠BAD，∴∠BAE＝∠CAD，∴∠EAB＝20°．故答案为：20．17．解：∵∠BAC＝90°，∠B＝60°，∴∠ACB＝90°﹣60°＝30°，∵△AB′C由△ABC绕点A顺时针旋转90°得到，∴AC′＝AC，∠C′AB′＝∠CAB＝90°，∠AC′B′＝30°，∴△ACC′为等腰直角三角形，∴∠AC′C＝45°，∴∠CC′B′＝∠AC′C﹣∠AC′B′＝45°﹣30°＝15°．故答案为15°．18．解：连接PP′，如图，∵△PAC绕点A逆时针旋转60°后，得到△P′AB，∴∠PAP′＝60°，PA＝P′A＝6，P′B＝PC＝10，∴△PAP′为等边三角形，∴PP′＝PA＝6，∠P′PA＝60°，在△BPP′中，P′B＝10，PB＝8，PP′＝6，∵62+82＝102，∴PP′2+PB2＝P′B2，∴△BPP′为直角三角形，且∠BPP′＝90°，∴∠APB＝∠P′PB+∠BPP′＝60°+90°＝150°．故答案为6，150°．19．解：∵点A′与点A关于点O对称，点B′与点B关于点O对称，∴线段AB与A′B′关于点O对称．∴AB∥A′B′，且AB＝A′B′故答案为：平行且相等．20．解：如图作CE⊥AB，垂足为E，情形①当点C在线段AB上时，1∵∠C＝90°，AB＝5，AC＝3，∴BC＝＝＝4，∵AB•CE＝AC•BC，∴CE ＝，∴EB ＝＝＝，∵BC ＝BC 1， ∴EC 1＝BC 1﹣EB ＝4﹣＝，∴tan ∠BC 1C ＝＝3．情形②当C 1′在AB 的延长线上时，tan ∠BC 1′C ＝＝＝．故答案为3或．21．解：∵点A 的坐标是（﹣1，1）， ∴OA ＝，线段OA （O 为坐标原点）绕点O 逆时针旋转135°得线段OB ，则B 一定在y 轴的负半轴上，且OB ＝OA ， 则B 的坐标是（0，﹣）．22．解：当正方形放在③的位置，即是中心对称图形．23．解：将点（0，1）绕原点顺时针旋转90°，所得的点在x轴的正半轴上，到原点的距离为1，因而该点的坐标为（1，0）．故答案为（1，0）．24．解：如图，由旋转的性质可知：AC＝AC'，∵D为AC'的中点，∴AD＝，∵ABCD是矩形，∴AD⊥CD，∴∠ACD＝30°，∵AB∥CD，∴∠CAB＝30°，∴∠C'AB'＝∠CAB＝30°，∴∠EAC＝30°，∴AE＝EC，∴DE＝，∴CE＝＝，DE＝，AD＝，∴＝．25．解：∵B（8，4），∴OA＝8，AB＝OC＝4，∴A′O＝OA＝8，A′B′＝AB＝4，tan∠COD＝＝，即＝，解得CD＝2，∴点D的坐标为（2，4），设经过点D的反比例函数解析式为y＝（k≠0），则＝4，解得k＝8，所以，经过点D的反比例函数解析式为y＝．故答案为：y＝．一天，毕达哥拉斯应邀到朋友家做客。
高一英语 (9、It的用法专项训练)
教师辅导讲义3.It is nearly half a century the first computer was invented.A. whenB. thatC. sinceD. until4.It_______ to accomplish the return journey.A. coast us 15 daysB. spent 15days for usC. was 15 daysD. took us 15 days5. ________ from Beijing to London!A. How long way it isB. What long way is itC. How long way is itD. What a long way it is6. ________ is reported in the newspaper, talks between the countries are making progress.A. ItB. AsC. ThatD. What7. ________ is known to all that China is rich in natural resources.A. ItB. ThatC. WhatD. As8. ________ quite a few techniques to learn language well.A. It seems to haveB. There seem to beC. There seems to haveD. It seems to be9.Someone is ringing the doorbell. Go and see .A. who is heB. who he isC. who is itD. who it is10. It was 7 o'clock he came here yesterday.A. thatB. whenC. beforeD. since11. _______ that I was watching TV when he came to see me.A. It happenedB. What happenedC. That happenedD. It was happened12.The chairman thought necessary to invite Professor Smith to speak at the meeting.A. thatB. itC. thisD. him13.The Foreign Minister said, "________ our hope that the two sides will work towards peace."A. This isB. There isC. That isD. It is14. _______ is reported in the newspaper that the terrible flood has caused a loss of 10 million yuan.A. ItB. ThisC. ThatD. As15.It's up to you whether we should go to the art exhibition right now.A. decidingB. to decideC. of decidingD. decide16.W as________ that I saw last night at the corner?A. it youB. not youC. youD. that yourself17.It is about two months James leaves school. He is going to be a lawyer.A. whenB. beforeC. sinceD. that18. _______ turn is ________ to clean the blackboard?A. Which... itB. Whose... itC. Which... thatD. Whose. .. that19.The seriously injured man has stopped breathing. will be no possibility of making him come to life.A. ItB. ThereC. ThatD. This20.Space exploration has been made with the development of modern science.A. it possibleB. it wasC. that being possibleD. possible21.To improve my spoken English, I make to recite a passage of English every day.A. a ruleB. it a ruleC. a rule thatD. a rule it is22.He moved to a new flat because is only five minutes' walk from the new flat to his office.A. itB. thisC. thatD. there23.It was________ s everal years I had an opportunity of seeing the bird again.A. for... beforeB. not for... thatC. for... whenD. not for... then。
新四级强化辅导-写作-U校园
第1章四级写作知多少课时3:专项训练同义词替换(填空)5题：1)a significant/an essential /a crucial2) well-behaved3)obvious/evident/apparent4)motivate/stimulate5)demonstrates/presents精确表达替换(填空)5题：6)professor/supervisor/tutor7) novel fairy tale8)roses/lilies/violets9) daily necessities 10)threw词组替换5题：11)am fond of /am keen on12)12)hold the view13)13)are supposed to/ought to14)14) The majority of15)15) cling to / adhere to /stick句子改写10题：16)It is too hard for him to study two foreign languages17) It is very dangerous for children to cross the busy street18）it is labor that creates the world19) It is practice that makes perfect20)Only by combining theory with practice can you make progress21)Only by doing so can we exist in a harmonious and disciplined society22) There is no denying that some of them are tedious and not trustworthy23）It is impossible to achieve your goal without great efforts24)Parks are to the city what lungs are to the body.25) Engines are to machines what hearts are to animals句子补写6题:26)Hong Kong is an overcrowded and commercialized cit27)Shakespeare, a man of little education, wrote plays and poems that are read all over the world28) 28) To maintain the ecological balance, we should avoid the destruction of natural habitats29)The train had stopped due to a mechanical problem30) They will be concerned to do the right thing-to dress properly, for instance.31) Travelling abroad is much easier nowadays, because the Internet has brought much convenience. For example people can get cheap flight tickets with Just a few clicks online.句子合并6题:32)The problem was so complicated that it took us nearly a month to solve it33) That the star didn’t turn up made us disappointed34)Though it was late, they continued working35)A satellite is an object, either natural or man-made, which travels in anorbit around another object in space36) Some children were playing games on the bank and there were some people rowingboats on the river.37) There was once a famous detective named Sherlock Holmes at the end of the 19th century.第2章应用文写作有方法课时5:专项训练1写作1题:Dear Li Ming,As we know, taking the college entrance examination has far-reaching significance to our lives, but I don't think it's necessary to feel severely stressed about itBelieve it or not, feeling stressed always has a negative effect on you. You may lose your appetite and may not want to go over the lessons when the examination approaches.Consequently,it will in turn distract you from your revision work, which is of great importance.There are some tips for you to relieve stress. First of all don' t repeat the very word"examination"every now and then in your mind. You should calm down and stay cool to focus on the revision of the subjects. Second, I suggest that you should listen to some Chinese classical music to ease our mind when you feel stressed. Third, walking around on campus, either alone or with friends, is also a good way to help you relax. In conclusion, you should prepare yourself in a relaxing atmosphere for the coming challenge.Wish you good luck .Sincerely yours,Wang gang课时6:专项训练2参考答案:Dear Prof Smith,On behalf of the Student Union, I would like to invite you to a lecture in No.2 Conference Room in our university at 7 pm, May 4th. The theme of the lecture is"Environmental Protection and Sustainable Development”.As we know, the world we live in is becoming increasingly inhospitable because of environmental destruction. So it is quite urgent for us to do something to protect our environment. We will also invite another five experts from other universities to participate in the lecture and give speeches. Since you are a well-known specialist in the field it would be our great honor if you could come and give us a speech. We believe that this lecture will contribute to environmental protection and sustainable development in our city.We sincerely hope you will join us to share your views. We are looking forward to a reply at your earliest convenience.Yours truly,Jim Green课时7:专项训练3参考答案:Dear Mr. SmithI am Li Ming, a new employee of your company. First of all, I'd like to show my great appreciation to you for offering me this job. I'll spare no effort to do it well.I 'm supposed to start work this Thursday but my right leg was injured because I was knocked down by a motorcycle yesterday. I went to hospital and had an examination. The doctor told me to have a rest for one week. I feel terribly sorry for not being able to work on the first day. I apologize or the inconvenience brought to the company. I wonder if it is all right that I start my work next Thursday. I will be very grateful for your agreement.I'm looking forward to your reply.Sincerely you,Li Ming第3章图表作文写作说诀窍课时9:专项训练参考答案:Talent ShowNowadays, talent shows have occupied a good proportion of screen time. However, people hold diversified opinions about the shows. According to a survey conducted in X city 59 percent of the interviewees believe that talent shows do more good than harm, whereas 41 percent think quite the opposite.The people in favor of the shows believe that they have given participants an equal chance to bring into their talents Talent shows in general provide a platform for people who want to stand in the spotlight. Besides, such programs are usually interactive with audience who vote for the winners Whereas those against the shows worry that the vulgar competition encourages an unhealthy expectation among young people of becoming famous overnight.In my opinion, some talent shows are no doubt a commercial success and an entertainment feast. And it would be subjective and one-sided to label them as"vulgar"or biased. I believe that the programs themselves are not harmful, as long as they are run properly and viewed with a light heart of enjoyment.课时10:专项训练2参考答案:These two graphs offer an interesting comparison of the changes in national income in G7 nations between two different time periods.The first graph looks at the years 2000--2007 In Germany, Italy and Japan, the income fluctuated through the years with small increases followed by small falls. For example, Italy saw slight increases of nearly 0.5 percent in 2000 and 2001 followed by bigger falls in 2002 and 2003, before it picked up again from 2004 to 2007 with the biggest rise of 2 percent. In comparison, the UK and Canada witnessed income growth in most years, with the UK hitting the highest 5 percent in 2000. France and the Us are the countries that enjoyed income increases all these years. These figures contrast sharply with those shown in the graph for 2008--2012, particularly for the UK and the US In the UK. four of the five years suffered income decreases with over 2 percent as the biggest fall in 201 1. Income increases in the us were smaller than most other countries with two years showing slight falls.The two graphs seem to reflect the changing economic conditions since 2000 and suggest that it had a significant impact on national income.第4章议论文写作寻突破课时13:专项训练1参考答案:Printed Book or E-book?As the computer and Internet technology head its way into everyone's daily life, the printed world gradually loses its dominance. You can see more people staring at Internet terminals than flipping through printed books.Unlike printed books, you can download what you want to read in just a few minutes and start reading e-books without leaving your room. Besides, e-books take up less space. You can store hundreds and thousands of them in your computer With modern technology e-books can be read anywhere at any time, such as on the bus, train, airplane or while waiting in line. Last but not least, e-books are eco-friendly by not consuming paper, ink, etc.However, in my point of view in no way does it signal the end of printed books. Actually, not all books are available in e-book form. And the high cost of an e-book reader prevents much of the worlds population from using e-books Moreover, therapidly changing technologies put old devices out of use, which lead to more waste and pollution.Therefore, printed books will still occupy a certain market share.课时14:专项训练2参考答案:Self-employment of College GraduatesAccording to a recent survey, a great number of university students can't find desired jobs upon graduation. The reason lies in the fact that too many university graduates have to compete for the limited job vacancies.One possible solution to the problem is to encourage students to start their own business after graduation. That is called self-employment. On the one hand, self-employment provides many graduates with opportunities to enrich themselves, better themselves and fulfill themselves. On the other hand, it can effectively relieve the government of the burden of offering adequate positions for university graduates.As far as I am concerned, it is quite hard for graduates to set up their own companies and actually only a small proportion of graduates are capable of doing so. Even if they have started their own businesses, they may still encounter lots of obstacles such as lack of funds and resources which often lead to a failure. Once they fail, their confidence may be severely undermined. Therefore. in order to tackle this problem, the government should try hard to increase the job opportunities and provide full support for self-employed graduates. Only in this way can graduates have better chance of achieving success课时15:专项训练3参考答案:The internet and the YouthThe Internet has brought young people much convenience For example, young people can obtain knowledge by distance learning. what's more, they can conveniently search for needed information for their school work if they have any confusion.They canalso contact their friends or relatives far away without leaving their homes at a very reasonable cost .However, the Internet is not always helpful or healthy. For instance, young people tend to spend too much time playing online games. instead of concentrating on their studies or going out with their friends in the real world. Some young people are also spiritually poisoned by unhealthy contents on the Internet, which might lead them into committing crimes.In my opinion, young people should realize that the Internet is a double-edged sword they should be able to judge what is beneficial and what is harmful to them. Making full use of the Internet, they also have to manage their time well, which requires a lot of self-discipline.课时16:专项训练4参考答案:Communication Is the Key to bridging the generation GapDifferent generations tend to have different states of mind as well as life experiences, and the rapid pace of social development makes this situation worse. As a result, there exists a generation gap between the old and the young. How to bridge the generation gap?I believe that the solution to the generation gap is communication. First of all, young people have much to learn from the old generation. The old people have more life experience to share with the young generation. Currently, many young people are unwilling to listen to the counsel of the elderly because their suggestions are often viewed as old-fashioned. However, it is not appropriate for the young o do so since the old can offer them helpful suggestions on how to live a successful life. Secondly, old people have much to learn from the young generation. Young people are energetic and ambitious, so they know the modern world very well. They may not have the wisdom of years, but their knowledge and dynamics are no less important. The elderly need to learn from the young how to work with modern technology and they can understand young people by communicating with them.If both generations are open to communication and are willing to listen to each other, we can get the best of both wisdom and harmony.课时17:专项训练5参考答案:Mobile Phones on CampusWith the development of science and technology, people have become increasingly aware of the necessity of using mobile phones. Even students on campus begin to use mobile phones and view them as a must. The following are my points of view.Mobile phones on the one hand are beneficial to student To begin with, they enable students to keep in touch with their parents and friends more conveniently and quickly Moreover. with their various functions such as WeChat media player and camera, mobile phones also make students' life more colorful and meaningful. On the other hand mobile phones have some negative effects on students. First, they cost students a great amount of money. Second, they may distract students from their study, which does harm to their future. Third, they sometimes become a nuisance especially when they are brought into class or the library, which disturbs the teacher and other students.As far as I am concerned, it is not good for students to use mobile phones especially for elementary and middle school students, since they do not have enough self-discipline to control themselves from overusing mobile phones. Parents should also be conscious of the guidance of using mobile phones.第5章真题讲练学经验课时19:专项训练1参考答案:1)Hi, Dong dong,We have been classmates for almost a year, and I fee compelled to write you this letter of gratitude .When I entered this university, I was quite shy, unwilling to communicate with others. so i kept my mouth shut like anoyster during the English oral practice. When I couldn't find the right wordsto convey my ideas, blood rushed to my cheeks. This was very bad for an oral English class.Seeing my problem, you offered me valuable help. You told me that you had been timid yourself in high school, but had gradually overcome the hindrance. Since confidence stems mainly from ability, you summarized dozens of useful expressions often used in oral drills for me to memorize Thus, I gradually found it easier to get my ideas across to others. what moved me most was that you arranged for some fellow students to make favorable comments on my spoken English in order to boost my morale-a fact I didn’t know until quite some time later when one student accidentally mentioned your arrangement, and instantly tears streamed down my cheeks.Dong dong, I take pride in having you as my classmate. You are my good brotherindeed.YoursWendu课时20:专项训练2参考答案Dear Mr. Lu ,You must be happy to learn that I have been admitted to the Physics Department of the Engineering University, which, you know, was my first choice. At this moment of delight, want to extend my deepest gratitude to you for your extraordinary contribution to my education over the past three years.It began in Senior One, when you taught us math-a subject that had been overwhelmingly tedious to me. But I was deeply impressed by your first class: an introduction to the importance of math, and some prominent mathematicians including Hua Luogeng. Anecdotes of these renowned mathematicians aroused my curiosity in math. From time to time, your witty remarks caused ripples of laughter among the students.In the following classes, I found your explanations of mathematical formulas quite easy-just a piece of cake Obviously you could explain logically, step by step, so that I could follow your line of thought almost effortlessly. This in turn, further sharpened my appetite for math. At the end of the semester. before I realized it,i scored among the highest on the exam.Thanks largely to my solid foundation in math, I was enrolled into this Engineering University. I do owe my success to you, my dear teacher. To prove I'm worthy of our kindness, I'll endeavor to achieve greater scholarly success in university.Yours ever,Li Xiao dong课时22:专项训练3参考答案:Mobile Phone Can't Replace Formal SchoolingAs we can see from the picture, a pupil with a mobile phone in his hand asks his mother why he is going to school if his phone already knows everything. Actually, the pupil overrates the role of the mobile phone, and fails to appreciate the significance of going to school.Can the mobile phone replace formal schooling? I don 't think so. To begin with, since formal schooling is provided by teachers experienced in educational philosophy and teaching strategies, students are expected to acquire systematic knowledge and develop healthy values and ethics under their instruction. By contrast, mobile phones can only provide bits and pieces of information. In addition, the classroom-based model of education offers students ample opportunities of face-to-face interaction with others, which will help to cultivate their interpersonal skills. Lastly, formal education equips students with the expertise needed for jobs.In short, the importance of formal schooling cannot be stated enough, so it is necessary for kids to go to school.课时23:专项训练4参考答案The Impact of Computer Overuse on Modern lifeAs is depicted in the picture, computers have become an integral part of modern life. Whether in the office, at home or during leisure time, the man is always hunching over a computer, which in turn haunts him in his dreams.Apparently, the cartoonist intends to draw our attention to the negative impacts of overusing computers on our everyday life.There is no doubt that computers have changed our life enormously and people nowadays depend on them for various purposes. However, the overuse of computers may adversely affect our social interaction and health. For one thing, the excessive use of computers can distract people so much that they lose contact with the reality and spend much less time on face-to-face interaction with people around them. For another, sitting in front of a computer for too long can cause back, neck and shoulder pains, eyestrain, and injuries of wrists, among other health problems.In conclusion, we should be alert to the dangers of using computers excessively while celebrating them as a kind of great tool.课时25:专项训练5参考答案:Learning Is a Daily Experience and a Lifetime MissionHenry Ford once said, " Anyone who stops learning is old whether at twenty or eighty. Anyone who keeps learning stays young. Undoubtedly, learning is a daily experience and a lifetime mission For instance. Karl Marx. the founder of scientific communism was known for his persistence in language learning throughout his life.Learning plays a significant role in our whole life and only by lifelong learning, can we keep up with the times. Firstly, n the modern age. knowledge to us is whatwater to fish. If we don’t keep learning, we won 't acquire up-to-date knowledge, and consequently we are doomed to be laggards Secondly, lifelong learning can make us more adaptable to the ever-changing world. Our world is mobile and things never stay the same It's important to continue learning so we can keep abreast of society’s changes. Thirdly, learning throughout life can provide us with more and better opportunities for professional development.To sum up, learning is a lifelong journey. If we commit ourselves to lifelong learning, we win; if we don' t, we lose.课时26:专项训练6参考答案The Importance of Being Participants in LifeAs a famous saying goes, " Never go out there to see what happens, go out there to make things happen. "Only when we participate more actively can we make things happen in the direction we anticipate.As is often the case, people who don 't hesitate to take actions to solve problems make great achievements. Examples are numerous, but I think the following one is convincing enough. Aiming to find drug therapy for malaria, Tu Youyou, together with her colleagues, eventually discovered a pure substance called"qinghaosu". Had she not taken prompt actions to discover a new approach to malaria treatment, she wouldn’t have been the first Chinese Nobel laureate in medicine.In summary, active participation is a key to our success in the ever-changing world. Therefore, we college students should be contributing participants in changing the world for the better.课时28:专项训练7参考答案:Dear Dad and Mom,On this Father's Day, I would like to express my heartfelt gratitude to you for your gift of my upbringing: You raised me not only physically, but also mentally and morally.I am now a student of a prestigious university, but that is not what matters most. Rather, what I can remember vividly is how you taught me to live and work independently, and the day I was elected by the classmates to be one of the three heavily on others: I wanted the teacher to provide tips for the homework, I asked fellow students to share ideas with me often turned to reference books to find not just answers but ready answers, so that I didn’t have to beat my brains to solve problems. It was you who dissuaded me from such lazy approaches. You ordered me to read articles and books about the success of self-made men who rose to fame in spite of their poor family background and fought their way out by surmounting seemingly insurmountable difficulties As a matter of fact. your complete devotion to your own work also left an unforgettable impression on my mind Compared with other young people of my age, I have achieved much more independence.I owe my development as an independent human being to my upbringing, which will surely exert a profound far-reaching impact on my future career development thank you from the bottom of my heart!Love ,Xiao dong第6章四级全真模拟课时29:四级笔试真题写作1题参考答案:Mobile Phone Can't Replace Formal SchoolingAs we can see from the picture, a pupil with a mobile phone in his hand asks his mother why he is going to school if his phone already knows everything. Actually, the pupil overrates the role of the mobile phone, and fails to appreciate the significance of going to school .Can the mobile phone replace formal schooling? I don’t think so. To begin with, since formal schooling is provided by teachers experienced in educational philosophy and teaching strategies, students are expected to acquire systematic knowledge anddevelop healthy values and ethics under their instruction. By contrast, mobile phones can only provide bits and pieces of information. In addition, the classroom-based model of education offers students ample opportunities of face-to-face interaction with others, which will help to cultivate their interpersonal skills. Lastly, formal education equips students with the expertise needed for jobs.In short, the importance of formal schooling cannot be stated enough, so it is necessary for kids to go to school.短对话8题2)A. The woman should go on playing chess3)D. Mary probably knows Sally’s new address.4)B. His notes are not easy to read5)D. The man had better choose another restaurant6)C. He has been looking forward to spring7)C. The man appreciates the woman's help8)B. Go to work on foot9)A. Temporary closing has disturbed the airport's operation长对话7题10) A. She listened to recordings of many European orchestras11) D. She began taking violin lessons as a small child12) A. It was the chance of a lifetime13) C. It has a chemical processing plant14) D. He is a salesman15) C. Mr Grand's personal assistant. D16) B. Provide details of their products and services短文理解10题17) B. His personal history is little known18) D. He was a member of the town council19) C. Possible sources of clues about him were lost in a20) A. Theft21) B. Have the right documents22) B. Use official transport23) C. Sell inexpensive products24) A. At a meeting of top British business people.25) D. Insulted26) B. There should be a limit to one's sense of humour听写填空10题27) prosperingdecade opposite 30)sustain 31) In simple terms 32)establish 33) reasonably 34) take into account 35)misleading 36) using up词汇理解10题 37)A 38)K 39)G41)D 42)H 43)J 44)O 45)E 46)C长篇阅读10题 47)K 48)A 49)G51)B 52)D 53)E 54)H仔细阅读10题57)B. It will protect them from sunburn58)A. It is ineffective in preventing melanomas59)D. Daily application of sunscreen helps reduce the incidence of melanomas60)C. It is not based on direct observation of the subjects61)A. Using both covering up and sunscreen62)B. Well-educated people tend to work longer63)B.A rapid technological advance64)A. Economic growth will slow down65)C. Even wealthy people must work longer to live comfortably in retirement66)D. Skills are highly valued regardless of age短文翻译1题67)参考答案:China is one of the oldest civilisations in the world. Many elements which make up the basis of modern world originate in/from China. Now with the world's fastest-growing economy China is experiencing a new industrial revolution China also starts the ambitious space exploration programme, which includes building a space station by 2020. Currently being one of the largest exporters in the world, China is attracting massive foreign investment. Meanwhile, it also invests billions of dollars overseas. In 201 1. China overtook Japan to become the world's second-largest economy.课时30:四级笔试真题2写作1题1)参考答案Learning Is a Daily Experience and a Lifetime MissionHenry Ford once said, "Anyone who stops learning is old, whether at twenty or eighty. Anyone who keeps learning stays young. " Undoubtedly, learning is a daily experience and a lifetime mission For instance. Karl Marx. the founder of scientificcommunism, was known for his persistence in language learning throughout his life.Learning plays a significant role in our whole life and only by lifelong learning, can we keep up with the times. Firstly in the knowledge age, knowledge is to us what water is to fish. If we don' t keep learning, we won 't acquire up-to-date knowledge, and consequently we are doomed to be laggards Secondly, lifelong learning can make us more adaptable to the ever-changing world. Our world is mobile and things never stay the same. It's important to continue learning so we can keep abreast of society's changes. Thirdly, learning throughout life can provide us with more and better opportunities for professional development.To sum up learning is a lifelong journey. If we commit ourselves to lifelong learning, we win; if we don,t, we lose.短对话8题2)B. They enjoyed the movie on space exploration3)A. At a gift shop4)C. He declined a job offer from the art gallery5)D. He will be unable to attend the birthday party6)B. Set a deadline for the staff to meet7)A. The way to the visitors parking8)D. He has benefited from exercise9) D. The secretaries in the man's company.长对话7题10)B. It is used by more people than English11)C. The influence of the British Empire12)A. It includes a lot of words from other languages13)C. To place an order.14)B. He is not familiar with the exact details of the goods.15)D. It depends on a number of factors16)C.Ring back when she comes to a decision.短文理解10题17)B. No one knows for sure when they came into being18)18)A. Carry ropes across rivers.19)D. To prove that lightning is electricity.20)C. He grew up in a poor single-parent family.21)B. Stupid22)A. Write two book reports a week23)B. She can speak several languages24)D. They have an intense interest in cross-cultural Interactions25)C. She was able to translate for a German sports judge26)A. Taste the beef and give her comment听写填空10题27)heavenly28)fascinating29)made up of30)Now and the31)combine with32) generally33)characteristics。
安全教育考试三级试题含答案专项训练题(5篇)
三级安全教育答案一．填空题：1．安全生产方针是：安全第一、预防为主。
2.建筑业频发“五大伤害’是高处坠落、物体打击、机械伤害、触电、坍塌事故。
其中高处坠落占40%-50%。
3.伤亡事故发生的主要原因是“三违’造成的，即违章指挥、违章作业、违反劳动纪律。
4．预防伤亡事故发生三不伤害是：不伤害自己、不伤害他人、不被他人伤害、不让他人被伤害。
5．坑（槽）沟边1米以内不准堆土堆料，不准停放机械。
6．开关箱周围不准堆放杂物，与被控制的固定电气设备距离不超过3米，以便发生故障及时切断电源。
7．中华人民共和国国家标准《高处作业分级》中规定：高处作业，凡在坠落高度基准面2米以上有可能坠落的高处进行得分作业，均称为高处作业。
8．常见安全标志可分为：指示、提示标志、禁止、警告标志四类。
9．正确使用安全带，是要求不准将安全带打结使用，要把安全带挂在牢靠处和应高挂抵用。
二、选择题1.C；2.B；3.C；4.A；5.B；6.A；7.C；8.A9.B；10.B；11.B；12.A；13.C；三、简答题1.进入施工现场为什么要戴好合格的安全帽？答：在施工现场工作，防止碰伤或坠落物砸伤头部，因此必须佩带合格的、无损坏的安全帽，并扣好下颚带。
2.为什么不允许穿拖鞋或光着脚进入施工现场？答：为防止刺伤、烫伤、扎伤脚，所以禁止穿拖鞋或光脚进入施工现场。
员工三级安全教育考试试题姓名：年月日得分：一、单项选择题：（共30题，每题2分。
每题的备选项中，只有一个最符合题意）1．《安全生产法》适用于在中华人民共和国领域内从事（ A ）活动的单位。
A．生产经营 B．经营 C．生产2．依照《安全生产法》的规定，生产经营单位必须依法参加工伤社会保险。
工伤保险费应由（ B ）缴纳。
A．从业人员 B．生产经营单位 C．单位和个人共同3．依照《安全生产法》和有关法律、法规的规定，国家实行生产安全事故（ B ）制度，追究生产安全事故责任人员的法律责任。
A．追究责任 B．责任追究 C．责任4．国家对在改善安全生产条件、防止生产安全事故、参加抢险救护等方面取得（ C ）成绩的单位和个人，给予奖励。
小学三年级上册数学应用题专项训练及答案
小学三年级上册数学应用题专项训练及答案1.小学三年级上册数学应用题专项训练及答案篇一1、用一根线正好围成一个边长是8厘米的正方形。
这根线长多少厘米？解题思路：已知条件是用一根线正好围成一个边长是8厘米的正方形。
所求问题是这根线长多少厘米？正方形的周长=边长×4，已知边长是8厘米，所以周长为8×4=32（厘米）答：这根线长32厘米。
2、小白兔拔了14个萝卜，小灰兔拔的是它的3倍。
小白兔比小灰兔少拔了多少个？解题思路：已知条件是小白兔拔了14个萝卜，小灰兔拔的是它的3倍。
所求问题：小白兔比小灰兔少拔了多少个？观察问题，要比较谁多谁少，用减法，第一步先求出两者的数量。
小白兔拔了14个萝卜，小灰兔拔的是14的3倍，即14×3=42（个），两者相差42-14=28（个）答：小白兔比小灰兔少拔了28个。
2.小学三年级上册数学应用题专项训练及答案篇二1、东风小学今年种柳树148棵，种的杨树是柳树棵数的3倍，种了多少棵杨树？148×3=444（颗）2、学校会议室有9排座位，每排能坐32人，一共能坐多少人？9×32=288（人）3、小小图书屋新购进儿童画册406册，每册8元，进这些画册一共用了多少元？406×8=3248（元）4、李叔叔一家8口人要去“凤凰山”风景旅游区游玩，带1200元买门票够吗？门票：没人140元140×8=1120（元）1120<1200够5、全校学生参加大扫除活动，一、二、三、四年级每个年级去了105人，五、六年级各去了120人，全校一共去了多少人？4×105=420(人）2×120=240（人）420+240=660（人）3.小学三年级上册数学应用题专项训练及答案篇三1、张明骑自行车去外婆家，如果每小时行6千米，3小时可以到达，如果想2小时到达，每小时要行多少千米？6×3÷2=9（千米）2、亮亮3分钟做了18道口算题，照这样的速度，他5分钟可以做几道？做54道要多少分钟？18÷3×5=30（道）54÷（18÷3）=9（分）3、张小蕊折千纸鹤，3分钟折了9个，照这样的速度，还要再折10分钟才能完成任务。
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专项训练31.（2008江苏）某种昆虫长翅（A ）对残翅（a ）为显性，直翅（B ）对弯翅（b ）为显性，有刺刚毛（D ）对无刺刚毛（d ）为显性，控制这3对性状的基因均位于常染色体上。
现有这种昆虫一个体基因型如下图所示，请回答下列问题。
（1）长翅与残翅、直翅与弯翅两对相对性状的遗传是否遵循基因自由组合定律，并说明理由： 。
（2）该昆虫一个初级精母细胞产生的精细胞的基因型为____________。
（3）该昆虫细胞有丝分裂后期，移向细胞同一极的基因有 。
（4）该昆虫细胞分裂中复制形成的两个D 基因发生分离的时期有 。
（5）为验证基因自由组合定律，可用来与该昆虫进行交配的异性个体的基因型分别是 。
2.（2010新课标）某种自花受粉植物的花色分为白色、红色和紫色。
现有4个纯合品种：l 个紫色(紫)、1个红色(红)、2个白色(白甲和白乙)。
用这4个品种做杂交实验，结果如下： 实验1：紫×红，F l 表现为紫，F 2表现为3紫：1红；实验2：红×白甲，F l 表现为紫，F 2表现为9紫：3红：4白；实验3：白甲×白乙，F l 表现为白，F 2表现为白；实验4：白乙×紫，F l 表现为紫，F 2表现为9紫：3红：4白。
综合上述实验结果，请回答：(1)上述花色遗传所遵循的遗传规律是 。
(2)写出实验1(紫×红)的遗传图解(若花色由一对等位基因控制，用A 、a 表示，若由两对等位基因控制，用A 、a 和B 、b 表示，以此类推)。
遗传图解为 。
（3）为了验证花色遗传的特点，可将实验2(红×白甲)得到的F 2植株自交，单株收获F 2中紫花植株所结的种子，每株的所有种子单独种植在一起可得到一个株系，观察多个这样的株系，则理论上，在所有株系中有4/9的株系F 3花色的表现型及其数量比为 。
3.（2009年广东）雄鸟的性染色体组成是ZZ ，雌鸟的性染色体组成是ZW 。
某种鸟羽毛的颜色由常染色体基因（A 、a ）和伴染色体基因（Z B 、Z b ）共同决定，其基因型与表现型的对应（1）黑鸟的基因型有 种，灰鸟的基因型有 种。
（2）基因型纯合的灰雄鸟与杂合的黑雌鸟交配，子代中雄鸟的羽色是 ，雌鸟的羽色是 。
（3）两只黑鸟交配，子代羽毛只有黑色和白色，则母本的基因型为 ，父本的基因型为 。
(4)一只黑雄鸟与一只灰雌鸟交配，子代羽毛有黑色、灰色和白色，则母本的基因型为 ，父本的基因型为 ，黑色、灰色和白色子代的理论分离比为 。
4.（2009年福建）某种牧草体内形成氰的途径为：前体物质→产氰糖苷→氰 。
基因A 控制（1）在有氰牧草（AABB ）后代中出现的突变那个体（AAbb ）因缺乏相应的酶而表现无氰性状，如果基因b与B的转录产物之间只有一个密码子的碱基序列不同，则翻译至mRNA的该位点时发生的变化可能是：编码的氨基酸，或者是。
（2）与氰形成有关的二对基因自由组合。
若两个无氰的亲本杂交，F1均表现为氰，则F1与基因型为aabb的个体杂交，子代的表现型及比例为。
（3）高茎与矮茎分别由基因E、e控制。
亲本甲（AABBEE）和亲本乙（aabbee）杂交，F1均表现为氰、高茎。
假设三对等位基因自由组合，则F2中能稳定遗传的无氰、高茎个体占。
（4）以有氰、高茎与无氰、矮茎两个能稳定遗传的牧草为亲本，通过杂交育种，可能无法获得既无氰也无产氰糖苷的高茎牧草。
请以遗传图解简要说明。
5.（2008四川）已知某植物的胚乳非糯（B）对糯（b）为显性，植株抗病（R）对感病（r）为显性。
某同学以纯合的非糯感病品种为母本，纯合的糯抗病品种为父本进行杂交实验，在母本植物上获得的F1种子都表现为非糯。
在无相应病原体的生长环境中，播种所有的F1种子，长出许多的F1植物，然后严格自交得到F2种子，以株为单位保存F2种子，发现绝大多数F1植株所结的F2种子都出现糯与非糯的分离，而只有一株F1植株（A）所结的F2种子全部表现为非糯，可见这株F1植株（A）控制非糯的基因是纯合的。
请回答：⑴从理论上说，在考虑两对性状的情况下，上述绝大多数F1正常自交得到的F2植株的基因型有_________种，表现型有___________种。
⑵据分析,导致A植株非糯基因纯合的原因有两种：一是母本自交，二是父本的一对等位基因中有一个基因发生突变。
为了确定是哪一种原因，可以分析F2植株的抗病性状，因此需要对F2植株进行处理。
这种处理是_______________________________。
如果是由于母本自交，F2植株的表现型为________________。
其基因型是___________；如果是由于父本控制糯的一对等位基因中有一个基因发生突变，F2植株的表现型为_______________________________，其基因型为_______________。
⑶如果该同学以纯合的糯抗病品种为母本，纯合的非糯感病品种为父本，进行同样的实验，出现同样的结果，即F1中有一株植株所结的F2种子全部表现为非糯，则这株植株非糯基因纯合的原因是_______________________________，其最可能的基因型为______________。
遗传病概率计算6.(2013海南卷)造成人类遗传病的原因有多种。
在不考虑基因突变的情况下，回答问题：（1） 21三体综合征一般是由于第21号染色体____异常造成的。
A和a是位于第21号染色体上的一对等位基因，某患者及其父、母的基因型依次为Aaa、AA和aa，据此可推断，该患者染色体异常是其____的原始生殖细胞减数分裂异常造成的。
（2）猫叫综合征是第5号同源染色体中的l条发生部分缺失造成的遗传病。
某对表现型正常的夫妇（丈夫的基因型为BB，妻子的基因型为bb）生出了一个患有猫叫综合征的孩子，若这个孩子表现出基因b的性状，则其发生部分缺失的染色体来自于____（填“父亲”或“母亲”）。
（3）原发性高血压属于____基因遗传病，这类遗传病容易受环境因素影响，在人群中发病率较高。
（4）就血友病和镰刀型细胞贫血症来说，如果父母表现型均正常，则女儿有可能患____，不可能患____。
这两种病的遗传方式都属于单基因____遗传。
7.（2010广东）克氏综合征是一种性染色体数目异常的疾病。
现有一对表现型正常的夫妇生了一个患克氏综合征并伴有色盲的男孩，该男孩的染色体组成为44+XXY。
请回答：（1）画出该家庭的系谱图并注明每个成员的基因型（色盲等位基因以B 和b 表示）。
（2）导致上述男孩患克氏综合征的原因是：他的（填“父亲”或“母亲”）的生殖细胞在进行分裂形成配子时发生了染色体不分离。
（3）假设上述夫妇的染色体不分离只是发生在体细胞中，①他们的孩子中是否会出现克氏综合征患者？②他们的孩子患色盲的可能性是多大？。
8.（2008江苏）下图为甲种遗传病（基因为A、a）和乙种遗传病（基因为B、b）的家系图。
其中一种遗传病基因位于常染色体上，另一种位于X染色体上。
请回答以下问题（概率用分数表示）。
（1）甲种遗传病的遗传方式为___________。
（2）乙种遗传病的遗传方式为___________。
（3）Ⅲ-2的基因型及其概率为。
（4）由于Ⅲ-3个体表现两种遗传病，其兄弟Ⅲ-2在结婚前找专家进行遗传咨询。
专家的答复是：正常女性人群中甲、乙两种遗传病基因携带者的概率分别为1/10000和1/100；H如果是男孩则表现甲、乙两种遗传病的概率分别是____________，如果是女孩则表现甲、乙两种遗传病的概率分别是___________；因此建议____________。
9.（2012江苏）人类遗传病调查中发现两个家系都有甲遗传病（基因为H、h）和乙遗传病(基因为T、t)患者，系谱图如下。
以往研究表明在正常人群中Hh基因型频率为10-4。
请回答下列问题（所有概率用分数表示）：(1)甲病的遗传方式为，乙病最可能的遗传方式为。
(2)若I-3无乙病致病基因，请继续以下分析。
①I-2的基因型为；II-5的基因型为。
②如果II-5与II-6结婚，则所生男孩同时患两种遗传病的概率为。
③如果II-7与II-8再生育一个女儿，则女儿患甲病的概率为。
④如果II-5与h基因携带者结婚并生育一个表现型正常的儿子，则儿子携带h基因的概率为。
10.（2011浙江）以下为某家族甲病（设基因为B、b）和乙病（设基因为D、d）的遗传家系图，其中II1，不携带乙病的致病基因。
请回答：（1）甲病的遗传方式为，乙病的遗传方式为。
I1的基因型是。
（2）在仅考虑乙病的情况下，III2与一男性为双亲，生育了一个患乙病的女孩。
若这对夫妇再生育，请推测子女的可能情况，用遗传图解表示。
遗传物质的传递11.（2010北京）科学家以大肠杆菌为实验对象，运用同位素示踪技术及密度梯度离心方法⑴要得到DNA中的N全部被放射性标记的大肠杆菌B，必须经过代培养，且培养液中的是唯一氮源。
⑵综合分析本实验的DNA离心结果，第组结果对得到结论起到了关键作用。
，但需把它与第组和第组的结果进行比较，才能说明DNA分子的复制方式是复制。
⑶分析讨论：①若子Ⅰ代DNA的离心结果为“轻”和“重”两条密度带，则“重带”DNA来自于，据此可判断DNA分子的复制方式不是复制。
②若将子Ⅰ代DNA双链分开后再离心，其结果（选填“能”或“不能”）判断DNA的复制方式。
③若在同等条件下将子Ⅱ代继续培养，子n代DNA离心的结果是：密度带的数量和位置，放射性强度发生变化的是带。
④若某次实验的结果中，子Ⅰ代DNA的“中带”比以往实验结果的“中带”略宽，可能的原因是新合成DNA单链中的N尚有少部分为。
12.（2011浙江）B基因可编码瘦素蛋白。
转录时，首先与B基因启动部位结合的酶是。
B基因刚转录出来的RNA全长有4500个碱基，而翻译成的瘦素蛋白仅由167个氨基酸组成，说明。
翻译时，一个核糖体从起始密码子到达终止密码子约需4秒钟，实际上合成100个瘦素蛋白分子所需的时间约为1分钟，其原因是。
若B基因中编码第105位精氨酸的GCT突变成ACT，翻译就此终止，由此推断，mRNA上的为终止密码子。
13.（2007四川）下面是某基因的部分碱基序列，序列Ⅰ为内含子的一部分，序列Ⅱ为外显子的一部分。
上列片段所编码蛋白质的氨基酸序列为“—甲硫氨酸－精氨酸－谷氨酸－丙氨酸－天冬氨酸－缬氨酸—”（甲硫氨酸的密码子是AUG）①该基因表达过程中，RNA的合成在中完成，此过程称为②请写出编码上述氨基酸序列的mRNA序列：。
③ 如果序列Ⅰ中箭头所指碱基对G//C被替换为T//A，该基因上列片段编码的氨基酸序列为：。
④如果序列Ⅱ中箭头所指碱基对G//C缺失，该基因上列片段编码的氨基酸序列为：。