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人教版高中生物课时跟踪检测(二十六) 细胞的分化

人教版高中生物课时跟踪检测(二十六)  细胞的分化

课时跟踪检测(二十六)细胞的分化[理解·巩固·落实]1.判断下列叙述的正误,对的打“√”,错的打“×”。

(1)细胞分化过程中细胞内的遗传物质种类发生了变化。

()(2)细胞分化的方向在胚胎早期已经决定,一般不能逆转。

()(3)克隆羊培育成功说明高度分化的动物细胞具有全能性。

()(4)植物组织培养说明高度分化的植物细胞仍然具有全能性。

()答案:(1)×(2)√(3)×(4)√2.下列有关细胞全能性的叙述,错误的是()A.受精卵在自然条件下能使后代细胞形成完整个体,因此全能性最高B.生物体内,细胞由于分化全能性不能表达C.卵细胞与受精卵一样,细胞未分化全能性很高D.植物细胞离体培养,在一定营养条件下能表现出全能性解析:选C受精卵是个体发育的起点,在自然条件下,通过细胞分裂和细胞分化形成完整个体,所以细胞全能性最高,A正确;正常情况下,多细胞生物体内的每一个体细胞都是由受精卵分裂、分化而来的,都含有发育成完整个体所必需的全套遗传物质,都具有全能性,但在个体发育过程中,因为基因的选择性表达,所以没有体现全能性,B正确;卵细胞是已分化的细胞,C错误;植物细胞在离体和一定营养条件下可表现出全能性,D正确。

3.(2021·聊城高一检测)下列能说明某细胞已经发生分化的是()A.进行ATP的合成B.进行蛋白质的合成C.存在血红蛋白D.存在呼吸氧化酶解析:选C特异性蛋白合成的实质在于基因的选择性表达,因此,判断某细胞是否已发生分化,关键看细胞的特异性蛋白是否合成。

血红蛋白是红细胞的特异性蛋白,具有运输氧气的作用,某细胞中存在血红蛋白说明该细胞已发生分化。

故选C。

4.细胞分化过程中,一般不会出现的是()A.细胞表面结构的改变B.细胞器种类和数量的改变C.蛋白质种类和数量的改变D.细胞核中遗传物质的改变解析:选D细胞分化的过程即基因选择性表达的过程,细胞核中遗传物质并未发生改变。

课时跟踪检测(二十六) 正弦定理和余弦定理

课时跟踪检测(二十六)  正弦定理和余弦定理

课时跟踪检测(二十六) 正弦定理和余弦定理[达标综合练]1.在△ABC 中,若A =60°,C =45°,c =3,则a =( ) A .1 B.322 C.233D .2解析:选B 由正弦定理得,a =c sin A sin C =322.2.△ABC 中,已知面积4S =a 2+b 2-c 2,则角C 的度数为( ) A. 135° B. 45° C. 60°D. 120° 解析:选B 由4S =a 2+b 2-c 2,得4×12ab sin C =2ab cos C ,解得tan C =1,又角C为△ABC 的内角,所以C =45°.3.在△ABC 中,如果A =60°,c =4,23<a <4,则此三角形有( ) A .无解 B .一解 C .两解D .无穷多解解析:选C 根据正弦定理,可得a sin A =csin C ,所以sin C =c ·sin A a =23a , 因为23<a <4,所以sin C ∈⎝⎛⎭⎫32,1, 又由c >a ,则60°<C <120°,有两个C 满足条件,所以此三角形有两解. 4.在△ABC 中, cos 2B 2=a +c2c ,则△ABC 的形状为( )A .正三角形B .直角三角形C .等腰或直角三角形D .等腰直角三角形解析:选B 因为cos 2B 2=1+cos B 2,所以1+cos B 2=a +c 2c ,有cos B =ac =a 2+c 2-b 22ac ,整理得a 2+b 2=c 2,故C =π2, △ABC 的形状为直角三角形.5.已知锐角三角形的三边长分别为1, 2, a ,则a 的取值范围是( ) A .(3,5) B .(3,5) C .(3,5)D .(5,3)解析:选A 要使锐角三角形的三边长分别为1, 2,a ,则保证2所对应的角和a 所对应的角均为锐角即可,即⎩⎪⎨⎪⎧1+a 2-42a>0,1+4-a24>0,a >0,解得3<a < 5.6.在△ABC 中,角A ,B ,C 的对边分别为a ,b ,c ,若a cos B +b cos A =4sin C ,则△ABC 的外接圆面积为( )A .16πB .8πC .4πD .2π解析:选C 设△ABC 的外接圆半径为R ,∵a cos B +b cos A =4sin C ,∴由余弦定理可得a ×a 2+c 2-b 22ac +b ×b 2+c 2-a 22bc =2c 22c =c =4sin C ,∴2R =csin C =4,解得R =2,故△ABC 的外接圆面积为S =πR 2=4π.7.如图,点D 是△ABC 的边BC 上一点,AB =7,AD =2,BD =1,∠ACB =45°,AC =________.解析:∵AB =7,AD =2,BD =1,∠ACB =45°, ∴由余弦定理可得cos ∠ADB =AD 2+BD 2-AB 22AD ·BD =4+1-72×2×1=-12,∵∠ADB ∈(0,π),∴∠ADB =120°, ∴∠ADC =180°-∠ADB =60°,∴由正弦定理可得AC =AD ·sin ∠ADC sin ∠ACB=2×3222= 6.答案: 68.在△ABC 中,给出下列5个命题:①若A <B ,则sin A <sin B ;②若sin A <sin B ,则A <B ;③若A >B ,则1tan 2A >1tan 2B ;④若A <B ,则cos 2A >cos 2B ;⑤若A <B ,则tan A 2<tan B 2.其中正确命题的序号是__________.解析:在△ABC 中,A <B ⇔a <b ⇔sin A <sin B ⇔sin 2A <sin 2B ⇔cos 2A >cos 2B ,故①②④正确;若A =75°,B =30°,则1tan 150°<1tan 60°,∴③错误;∵0<A <B <π,∴0<A 2<B 2<π2,∴tan A 2<tan B2,故⑤正确.答案:①②④⑤9.(2019·浙江高考)在△ABC 中,∠ABC =90°,AB =4,BC =3,点D 在线段AC 上.若∠BDC =45°,则BD =________,cos ∠ABD =________.解析:如图,易知sin C =45,sin A =35,cos A =45.在△BDC 中,由正弦定理可得BD sin C =BC sin ∠BDC ,∴BD =BC ·sin Csin ∠BDC=3×4522=1225. ∴cos ∠ABD =cos(45°-A )=cos 45°cos A +sin 45°sin A =22×45+22×35=7210. 答案:1225 721010.已知△ABC 中,角A ,B ,C 的对边分别为a ,b ,c ,且2cos C (a cos C +c cos A )+b =0.(1)求角C 的大小;(2)若b =2,c =23,求△ABC 的面积. 解:(1)∵2cos C (a cos C +c cos A )+b =0,∴由正弦定理可得2cos C (sin A cos C +sin C cos A )+sin B =0, ∴2cos C sin(A +C )+sin B =0,即2cos C sin B +sin B =0, 又0°<B <180°,∴sin B ≠0,∴cos C =-12,又0°<C <180°,∴C =120°.(2)由余弦定理可得(23)2=a 2+22-2×2a cos 120°=a 2+2a +4,又a >0,∴解得a =2,∴S △ABC =12ab sin C =3,∴△ABC 的面积为 3.11.△ABC 的内角A ,B ,C 的对边分别为a ,b ,c .已知△ABC 的面积为a 23sin A .(1)求sin B sin C ;(2)若6cos B cos C =1,a =3,求△ABC 的周长. 解:(1)由题设得12ac sin B =a 23sin A ,即12c sin B =a 3sin A. 由正弦定理得12sin C sin B =sin A 3sin A ,故sin B sin C =23.(2)由题设及(1)得cos B cos C -sin B sin C =-12,即cos(B +C )=-12.所以B +C =2π3,故A =π3.由题设得12bc sin A =a 23sin A,即bc =8.由余弦定理得b 2+c 2-bc =9,即(b +c )2-3bc =9, 解得b +c =33.故△ABC 的周长为3+33.12.(2019·全国卷Ⅲ)△ABC 的内角A ,B ,C 的对边分别为a ,b ,c .已知a sin A +C2=b sin A .(1)求B ;(2)若△ABC 为锐角三角形,且c =1,求△ABC 面积的取值范围. 解:(1)由题设及正弦定理得sin A sin A +C2=sin B sin A .因为sin A ≠0,所以sin A +C2=sin B .由A +B +C =180°, 可得sin A +C 2=cos B 2,故cos B 2=2sin B 2cos B2.因为cos B 2≠0,所以sin B 2=12,所以B =60°.(2)由题设及(1)知△ABC 的面积S △ABC =34a . 由(1)知A +C =120°,由正弦定理得a =c sin A sin C =sin (120°-C )sin C =32tan C +12.由于△ABC 为锐角三角形, 故0°<A <90°,0°<C <90°.结合A +C =120°,得30°<C <90°, 所以12<a <2,从而38<S △ABC < 32.因此△ABC 面积的取值范围是⎝⎛⎭⎫38,32. [素养强化练]1.[数学运算]已知在△ABC 中,角A ,B ,C 所对的边分别为a ,b ,c ,b cos ∠BCA =a ,点M 在线段AB 上,且∠ACM =∠BCM .若b =6CM =6,则cos ∠BCM =( )A.104B.34C.74D.64解析:选B 设∠ACM =∠BCM =θ,则∠BCA =2θ. 又a =b cos ∠BCA ,b =6CM =6, ∴a =6cos 2θ,CM =1.则由面积关系S △ACM +S △BCM =S △ABC , 得12×6×1×sin θ+12×1×6cos 2θ×sin θ =12×6×6cos 2θ×sin 2θ,∴sin θcos θ(4cos θ-3)(3cos θ+2)=0. ∵0<θ<π2,∴cos θ=34,故选B.2.[数学建模]线段的黄金分割点定义:若点C 在线段AB 上,且满足AC 2=BC ·AB ,则称点C 为线段AB 的黄金分割点.在△ABC 中,AB =AC ,A =36°,若角B 的平分线交边AC 于点D ,则点D 为边AC 的黄金分割点.利用上述结论,可以求出cos 36°=( )A.5-14B.5+14C.5-12 D.5+12解析:选B 设AB =2,AD =x , 又AB =AC ,所以CD =2-x .由黄金分割点的定义可得AD 2=AC ·CD , 即x 2=2·(2-x ),解得AD =5-1. 在△ABD 中,由余弦定理得cos 36°=AD 2+AB 2-BD 22·AD ·AB =(5-1)2+22-(5-1)22×(5-1)×2=5+14.故选B. 3.[数学运算]已知a ,b ,c 分别是△ABC 三个内角A ,B ,C 所对的边,且a cos C +12c=b .(1)求A ;(2)若a =1,求△ABC 的周长l 的取值范围. 解:(1)∵a cos C +12c =b ,由正弦定理得sin A cos C +12sin C =sin B .又∵sin B =sin(A +C )=sin A cos C +cos A sin C , ∴12sin C =cos A sin C , ∵sin C ≠0,∴cos A =12.又∵0<A <π,∴A =π3.(2)由正弦定理得b =a sin B sin A =2sin B 3,c =2sin C3,∴l =a +b +c =1+23(sin B +sin C ) =1+23[sin B +sin(A +B )] =1+2⎝⎛⎭⎫32sin B +12cos B =1+2sin ⎝⎛⎭⎫B +π6.∵A =π3,∴B ∈⎝⎛⎭⎫0,2π3,∴B +π6∈⎝⎛⎭⎫π6,5π6, ∴sin ⎝⎛⎭⎫B +π6∈⎝⎛⎦⎤12,1. 故△ABC 的周长l 的取值范围为(2,3].。

(江苏物理总复习)课时跟踪检测(二十六) 电源 闭合电路的欧姆定律

(江苏物理总复习)课时跟踪检测(二十六)  电源  闭合电路的欧姆定律

课时跟踪检测(二十六)电源闭合电路的欧姆定律一、立足主干知识,注重基础性和综合性1.某无线充电器的输出额定电压为5 V,输出额定电流为2 A。

某款手机的电池容量为4 000 mAh,额定工作电压为4 V。

则()A.无线充电器的内阻为2.5 ΩB.无线充电器以额定电流工作时,发热功率为10 W×104 J×104 J解析:选C充电器内阻和充电器发热功率无法用题中信息求出,故A、B错误;电池充满电后电荷量q=4 000 mAh=4×3 600 C×104C,电池可释放的化学能E=qU×104××104×104 J,选项D错误。

2.(2020·盐城三模)电热水器金属内胆出水口加接一段曲长管道,在电热水器漏电且接地线失效时,能形成“防电墙”,保障人的安全。

如图所示,当热水器漏电且接地线失效时,其金属内胆与大地间电压为220 V,由于曲长管道中水具有电阻(简称“隔电电阻”),因而人体两端的电压不高于12 V,下列说法正确的是()A.曲长管道应选用导电性能好的材料制成B.曲长管道应选用不易导电的材料制成C.“隔电电阻”大于“人体电阻”,且两者并联D.热水器漏电且接地线失效时,“防电墙”使人体内无电流通过解析:选B要使人体两端的电压不高于12 V,漏电电流通过曲长管道时损失的电压要足够大,所以曲长管道应选用不易导电的材料制成,选项A错误,B正确;“隔电电阻”大于“人体电阻”,且两者串联,选项C错误;热水器漏电且接地线失效时,“防电墙”可使人体内有很微弱的电流通过,不会造成人体触电,保障人的安全,选项D错误。

3.(2021·武汉模拟)如图所示,电源电动势为4 V,内阻为1 Ω,电阻R1=3 Ω,R2=R3=4 Ω,R4=8 Ω,电容器C=6.0 μF,闭合S电路达稳定状态后,电容器极板所带电荷量为()×10-5 C×10-5 C ×10-5 C ×10-5 C 解析:选A 由电路结构可知,电路中的总电阻为R 总=R 1+r +R 4(R 2+R 3)R 2+R 3+R 4=8 Ω,电路中的总电流为I =E R 总=0.5 A ,电容器两极板间的电势差为U C =U R 1+U R 2=IR 1+I 2R 2=2.5 V ,电容器极板所带电荷量为Q =CU C ×10-5 C ,故A 正确,B 、C 、D 错误。

高考物理复习高三一轮复习:课时跟踪检测26电流 电阻 电功 电功率

高考物理复习高三一轮复习:课时跟踪检测26电流 电阻 电功 电功率

高考物理复习课时跟踪检测(二十六) 电流电阻电功电功率高考常考题型:选择题+计算题1.如图1所示,a、b分别表示由相同材料制成的两条长度相同、粗细均匀电阻丝的伏安特性曲线,下列判断中正确的是( )A.a代表的电阻丝较粗B.b代表的电阻丝较粗C.a电阻丝的阻值小于b电阻丝的阻值图1D.图线表示的电阻丝的阻值与电压成正比2.(2012·浙江高考)功率为10 W的发光二极管(LED灯)的亮度与功率为60 W的白炽灯相当。

根据国家节能战略,2016年前普通白炽灯应被淘汰。

假设每户家庭有2只60 W的白炽灯,均用10 W的LED灯替代。

估算出全国一年节省的电能最接近( )A.8×108 kW·h B.8×1010 kW·hC.8×1011 kW·h D.8×1013 kW·h3.(2012·北京东城模拟)如图2甲所示,在材质均匀的圆形薄电阻片上,挖出一个偏心小圆孔。

在彼此垂直的直径AB和CD两端引出四个电极A、B、C、D。

先后分别将A、B或C、D接在电压恒为U的电路上,如图乙和图丙所示。

比较两种接法中电阻片的热功率大小,应有( )图2A.两种接法电阻片热功率一样大B.接在AB两端电阻片热功率大C.接在CD两端电阻片热功率大D.无法比较4.铜的摩尔质量为m,密度为ρ,每摩尔铜原子中有n个自由电子,今有一根横截面积为S的铜导线,当通过的电流为I时,电子平均定向移动的速率为( )A.光速c B.I neSC.ρIneSmD.mIneSρ[5.(2013·大同模拟)一台国产封闭型贮水式电热水器的铭牌上所列的主要技术参数如下表所示。

根据表( )A.6.8 A B.0.15 AC.4.4 A D.0.23 A6. (2012·北京西城期末)如图3所示电路中,电源电动势为E,内阻为r,电动机内阻为R1。

高三英语一轮复习课时作业26:Unit 1《Art》(新人教版选修6)

高三英语一轮复习课时作业26:Unit 1《Art》(新人教版选修6)

Ⅰ.多项选择1.The idea of working abroad really ________ me, and I'm trying to apply for a job abroad.A.adapts to B.relates toC.responds to D.appeals to[解析]句意:去国外工作的想法吸引着我,我正试图在国外找到一份工作。

appeal to 意为“有吸引力”,符合句意。

adapt to 适应(新环境等);relate to sb./sth.理解或同情某人(某事物);respond to 回应,反应。

[答案]D2.John applied for the post of Eliot's secretary.Does he______ the necessary patience and ability to do the job well?A.perform B.possessC.observe D.support[解析]句意:John 申请做Eliot 的秘书。

他有做好这项工作必备的耐性和能力吗?possess 具有,拥有,符合句意。

perform 表演,演奏;observe 观察,观测;support 支持,支撑。

[答案]B3.(2012·蚌埠二中期中考试)Rivera Street is dark ________ the light from 14-year-old Lona Zhao's upstairs bedroom.A.instead of B.in spite ofC.except for D.but for[解析]except for 除了,用来对前面的情况进行校正说明。

[答案]C4.He's one of those early birds.It's ________ of him to get up early.A.practical B.humorousC.rude D.typical[解析]It is typical of sb.to do sth.某人做……是他的特征。

正弦定理和余弦定理26

正弦定理和余弦定理26

课时跟踪检测(二十六)正弦定理和余弦定理[高考基础题型得分练]1.在△ABC中,若AB=13,BC=3,∠C=120°,则AC=() A.1 B.2 C.3 D.4答案:A解析:设△ABC中,角A,B,C的对边分别为a,b,c,则a=3,c=13,∠C=120°,由余弦定理,得13=9+b2+3b,解得b=1,即AC=1.2.两座灯塔A和B与海岸观察站C的距离相等,灯塔A在观察站南偏西40°,灯塔B在观察站南偏东60°,则灯塔A在灯塔B的()A.北偏东10°B.北偏西10°C.南偏东80°D.南偏西80°答案:D解析:由条件及题图可知,∠A=∠CBA=40°,又∠BCD=60°,所以∠CBD=30°,所以∠DBA=10°,因此灯塔A在灯塔B南偏西80°.3.[2018·山西临汾五校联考]在△ABC中,角A,B,C所对的边分别为a,b,c,若b cos A+a cos B=c2,a=b=2,则△ABC的周长为()A.5 B.6 C.7 D.7.5答案:A解析:由正弦定理,得 sin B cos A +sin A cos B =c sin C , 即sin(A +B )=sin C =c sin C , 又sin C >0,∴c =1,故周长为a +b +c =2+2+1=5,故选A.4.[2018·东北三省哈尔滨、长春、沈阳、大连四市联考]已知△ABC 中,内角A ,B ,C 的对边分别为a ,b ,c ,a 2=b 2+c 2-bc ,bc =4,则△ABC 的面积为( )A.12 B .1 C.3 D .2 答案:C解析:∵a 2=b 2+c 2-bc ,∴cos A =12,∴A =π3,又bc =4,∴△ABC 的面积为12bc sin A =3,故选C.5.在△ABC 中,已知b =40,c =20,C =60°,则此三角形的解的情况是( )A .有一解B .有两解C .无解D .有解但解的个数不确定 答案:C解析:由正弦定理,得b sin B =csin C ,∴sin B =b sin Cc =40×3220=3>1.∴角B 不存在,即满足条件的三角形不存在.6.[2018·东北三省三校联考]△ABC 的内角A ,B ,C 的对边分别为a ,b ,c ,则“a >b ”是“cos 2A <cos 2B ”的( )A .充分不必要条件B .必要不充分条件C .充要条件D .既不充分也不必要条件 答案:C解析:因为在△ABC 中,a >b ⇔sin A >sin B ⇔sin 2A >sin 2B ⇔2sin 2A >2sin 2B ⇔1-2sin 2A <1-2sin 2B ⇔cos 2A <cos 2B .所以“a >b ”是“cos 2A <cos 2B ”的充分必要条件.7.[2017·安徽淮北二模]在△ABC 中,角A ,B ,C 的对边分别为a ,b ,c ,若a 2=3b 2+3c 2-23bc sin A ,则C =________.答案:π6解析:由余弦定理,得a 2=b 2+c 2-2bc cos A ,所以b 2+c 2-2bc cosA =3b 2+3c 2-23bc sin A ,整理得3sin A -cos A =b 2+c2bc ,即2sin ⎝ ⎛⎭⎪⎫A -π6=b 2+c 2bc ≥2,因此b =c ,A -π6=π2,得A =2π3,所以C =π-2π32=π6.8.[2018·江西南昌二中模拟]在△ABC 中,如果cos(B +A )+2sin A sin B =1,那么△ABC 的形状是________.答案:等腰三角形解析:∵cos(B +A )+2sin A sin B =1, ∴cos A cos B +sin A sin B =1, ∴cos(A -B )=1,在△ABC 中,A -B =0⇒A =B , ∴△ABC 是等腰三角形.9.[2018·陕西八校联考]设△ABC 的三边长分别为a ,b ,c ,面积为S ,且满足S =a 2-(b -c )2,b +c =8,则S 的最大值为________.答案:6417解析:∵S =a 2-(b -c )2,b +c =8, ∴12bc sin A =2bc -(b 2+c 2-a 2) =2bc -2bc cos A , 即sin A +4cos A =4.联立⎩⎨⎧sin A +4cos A =4,sin 2A +cos 2A =1,解得sin A =817,∴S =12bc sin A =417bc ≤417×⎝ ⎛⎭⎪⎪⎫b +c 22=6417, 当且仅当b =c =4时等号成立.10.如图,为测得河岸塔AB 的高,先在河岸上选一点C ,使C 在塔底B 的正东方向上,测得点C 到点A 的仰角为60°,再由点C 沿北偏东15°方向走10米到位置D ,测得∠BDC =45°,则塔AB 的高是________米.答案:106解析:在△BCD 中,CD =10,∠BDC =45°, ∠BCD =15°+90°=105°,∠DBC =30°, 由正弦定理得BC sin 45°=CDsin 30°, 所以BC =CD sin 45°sin 30°=10 2. 在Rt △ABC 中,tan 60°=ABBC , AB =BC tan 60°=106(米).[冲刺名校能力提升练]1.在△ABC 中,内角A ,B ,C 所对的边分别是a ,b ,c ,若c 2 =(a -b )2+6,C =π3,则△ABC 的面积是( )A .3 B.932 C.332 D .3 3 答案:C解析:∵c 2=(a -b )2+6,∴c 2=a 2+b 2-2ab +6.① ∵C =π3,∴c 2=a 2+b 2-2ab cos π3=a 2+b 2-ab .② 由①②,得-ab +6=0,即ab =6. ∴S △ABC =12ab sin C =12×6×32=332.2.[2018·江西南昌一模]在△ABC 中,角A ,B ,C 所对的边分别是a ,b ,c ,若c =1,B =45°,cos A =35,则b =( )A.53B.107C.57D.5214 答案:C解析:因为cos A =35, 所以sin A =1-cos 2A =1-⎝ ⎛⎭⎪⎫352=45, 所以sin C =sin[180°-(A +B )] =sin(A +B )=sin A cos B +cos A sin B =45cos 45°+35sin 45°=7210.由正弦定理b sin B =csin C ,得 b =17210×sin 45°=57. 3.[2017·河北武邑三模]在△ABC 中,B =π4,角A 的平分线AD 交BC 于点D ,设∠BAD =α,sin α=55.(1)求sin C ;(2)若BA →·BC →=28,求AC 的长. 解:(1)因为α∈⎝ ⎛⎭⎪⎫0,π2,sin α=55, 所以cos α=1-sin 2α=255,则sin ∠BAC =sin 2α=2sin αcos α=2×55×255=45, 所以cos ∠BAC =cos 2α=2cos 2α-1=2×45-1=35,sin C =sin ⎣⎢⎡⎦⎥⎤π-⎝ ⎛⎭⎪⎫π4+2α=sin ⎝ ⎛⎭⎪⎫π4+2α=22cos 2α+22sin 2α=22×35+22×45=7210.(2)由正弦定理,得AB sin C =BC sin ∠BAC ,即AB 7210=BC45,所以AB =728BC .因为BA →·BC →=28,所以AB ×BC ×22=28, 由以上两式解得BC =42,由AC sin B =BC sin ∠BAC ,AC 22=BC 45,所以AC =5.4.如图所示,摄影爱好者S 在某公园A 处,发现正前方B 处有一立柱,测得立柱顶端O 的仰角和立柱底部B 的俯角均为π6.设S的眼睛到地面的距离为3米.(1)求摄影爱好者到立柱的水平距离和立柱的高度;(2)立柱的顶端有一长2米的彩杆MN 绕其中点O 在S 与立柱所在的平面内旋转.摄影爱好者有一视角范围为π3的镜头,在彩杆转动的任意时刻,摄影爱好者是否都可以将彩杆全部摄入画面?请说明理由.解:(1)作SC 垂直OB 于C ,则∠CSB =π6,∠ASB =π3.又SA =3,故在Rt △SAB 中,可求得BA =3, 即摄影爱好者到立柱的水平距离为3米. 由SC =3,∠CSO =π6,在Rt △SCO 中,可求得OC = 3. 因为BC =SA =3,故OB =23, 即立柱高为23米.(2)连接SM ,SN ,设SN =a ,SM =b . 由(1)知SO =23, 在△SOM 和△SON 中, cos ∠SOM =-cos ∠SON ,即(23)2+1-b 22×23×1=-(23)2+1-a 22×23×1,可得a 2+b 2=26.在△MSN 中,cos ∠MSN =a 2+b 2-222ab =11ab ≥22a 2+b 2=1113>12,当且仅当a =b 时等号成立.又∠MSN ∈(0,π),则0<∠MSN <π3. 故摄影爱好者S 可以将彩杆全部摄入画面.。

课时跟踪检测(二十六) 神经调节

课时跟踪检测(二十六) 神经调节

课时跟踪检测(二十六)神经调节一、单项选择题1.(2020·武汉调研)反射是神经调节的基本方式,下列关于反射的叙述,正确的是() A.望梅止渴、排尿反射都需要大脑皮层参与才能完成B.一些反射可以形成也可以消失,比如学生听到铃声后急速赶往教室C.条件反射一定需要神经中枢参与,非条件反射则不一定D.高级中枢控制的反射一定是条件反射解析:选B望梅止渴是条件反射,需要大脑皮层的参与才能完成,但排尿反射是非条件反射,无需大脑皮层的参与也能完成,A错误;条件反射可以形成也可以消失,如学生听到铃声急速赶往教室,B正确;无论是条件反射还是非条件反射,都需要在神经中枢的参与下才能完成,C错误;脑中的神经中枢都是高级中枢,但其中一些神经中枢控制的反射,如脑干中的呼吸中枢控制的反射是非条件反射,D错误。

2.某学校组织学生体检,有位同学看到自己的体检报告中多项指标不正常,感到非常紧张,引起心跳加速、呼吸急促,此时为了平复心跳和呼吸,该同学体内发生的生理调节过程为()A.在交感神经的支配下,心率减慢,支气管扩张B.在副交感神经的支配下,心率加快,支气管收缩C.在交感神经的支配下,心率加快,支气管扩张D.在副交感神经的支配下,心率减慢,支气管收缩解析:选C由于此时该同学非常紧张,引起心跳加速、呼吸急促,此时为了平复心跳和呼吸,通过交感神经的支配下,心率加快,支气管扩张,可恢复正常。

3. (2020·蚌山区月考)神经损伤后产生的信号会激活脑室下区的神经干细胞,这些细胞可以向脑内病灶迁移和分化,从而实现组织修复。

下列有关神经细胞的叙述,错误的是() A.实现组织修复的过程是基因选择性表达的过程B.损伤信号使神经干细胞膜内K+/Na+的值减小C.神经细胞膜上都含有相同种类的神经递质受体D.神经细胞释放神经递质的方式与胰岛素的分泌方式相同解析:选C实现组织修复的过程是神经干细胞的分化过程,细胞分化的实质是基因选择性表达,A正确;损伤信号刺激神经干细胞,使神经干细胞产生动作电位,Na+大量流入细胞内,则细胞内K+/Na+的值减少,B正确;神经递质有兴奋性的,也有抑制性的,突触后膜上的受体具有特异性,神经细胞膜上神经递质受体不完全相同,C错误;神经细胞释放神经递质的方式是胞吐,胰岛B细胞分泌胰岛素这种大分子物质的方式也是胞吐,D正确。

高中语文《外国诗歌散文欣赏》课时跟踪检测(二十六) 奴 性

高中语文《外国诗歌散文欣赏》课时跟踪检测(二十六) 奴 性

课时跟踪检测(二十六)奴性一、基础巩固1.下列词语中加点的字,注音全都正确的一项是()A.呻吟.(yín)床褥.(rù)喁.喁私语(yú) 酩酊.大醉(dīnɡ)B.豆豉.(chǐ) 髑.髅(dú)扺.掌而谈(zhǐ) 曲.径通幽(qū)C.勾.当(ɡòu)订.正(dīnɡ)一差.二错(chā)拾.级而上(shè)D.彷.徨(pánɡ) 藏匿.(nì)相.机行事(xiànɡ) 疾风劲.草(jìn)解析:选B A项,“酊”应读“dǐnɡ”;C项,“订”应读“dìn ɡ";D项,“劲”应读“jìng"。

2.下列词语中没有错别字的一项是()A.怯懦拉拉队融会贯通到处传诵B.竭磬美滋滋积年累月大展鸿图C.咒詈照像机委曲求全要言不烦D.草履金刚钻以逸待劳出奇致胜解析:选A B项,“磬”应为“罄”;C项,“像”应为“相”;D项,“致"应为“制”。

3.依次填入下列句子横线上的词语,最恰当的一项是( )①人是生活的奴隶.奴性用凌辱遮挡住人们的永昼,用血泪________了人们的长夜。

②他经常利用学习的________苦练篮球技术,现在已成为校队队员。

③爷爷说他忘不了那一段________的往事,也忘不了曾帮助过他的人。

A.湮没间隙心酸B.湮没间歇辛酸C.淹没间歇心酸D.淹没间隙辛酸解析:选D 湮没:埋没。

淹没:(大水)漫过,盖过.间隙:名词,空隙.间歇:动词,动作、变化等每隔一定时间停止一会儿。

心酸:心里悲痛。

辛酸:辣和酸,比喻痛苦悲伤。

4.下列语句中,标点符号使用正确的一项是( )A.太阳花的三朵花是信号,号音一起,跟在后边的便一发而不可挡。

大朵、小朵、单瓣、复瓣、红、黄、蓝、粉一齐开放。

B.《奴性》是纪伯伦的代表作,选自《纪伯伦全集》.(人民文学出版社2000年版)C.一时间,“黑丝带(中国第四代战机)"成为国内外关注的焦点,甚至有大批军迷千里迢迢赶赴成都“助威",不少无法到现场观看的军迷十分羡慕有幸现场观摩的“爬墙党”.D.见春花而喜年少,见秋霜而叹白头,见旷野而遥想塞外,见小溪而梦回江南:中国的诗人多是因“物”而缘情的。

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课时跟踪检测(二十六)ArtⅠ.单项填空1.—Do you think I should join the singing group, Mary?—________ If I were in your shoes, I certainly would.A.None of your business.B.It depends.C.Why not? D.I don't think so.2.Tom wasn't good at physics at first, but his physics has improved ________ since the new teacher began teaching him.A.a great deal B.scores ofC.plenty of D.a great many3.(2013·西安八校三联)—What do you think of she Spring Festival Gala of the Snake Year?—To be frank, it didn't ________ me much.A.appeal to B.belong toC.occur to D.refer to4.(2013·高新一中模拟)It's ________ of him to set his aim high but do little, so he is always leaving things undone.A.controversial B.typicalC.conventional D.evident5.(2013·邯郸市高三质检)What worries her most is that her son, who is twenty years old, is not interested in anything and doesn't have a(n) ________ aim of life.A.specific B.ridiculousC.negative D.allergic6.It is known to all that ________ you exercise regularly, you won't stay healthy.A.because B.unlessC.now that D.in case7.(2013·榆林一中第一次诊断)After decades of effort, the city is still trying to ________ how to ban smoking in public places.A.look through B.get throughC.figure out D.take out8.John is now working as an interpreter because he ________ an unusual ability to learn languages quickly.A.performs B.possessesC.observes D.supports9.(2013·浙大附中高三质检)Despite the short stay in this foreign country, he has soon________ himself to the new environment.A.attended B.adoptedC.adapted D.admitted10.(2013·银川二中高三模拟)The noise outside is nearly driving me mad. I wish they ________ that music down.A.had turned B.have turnedC.will turn D.would turn11.Having practiced for months, Bob Beamon broke the world long jump record at his first ________ in the 1968 Olympic final in Mexico.A.attempt B.desireC.intention D.sight12.(2013·宁波高三质检)—You need to start exercising again, I guess.—Well, I ________ to eat less recently.But as you know, my mother is such a good cook.A.have been attempting B.had attemptedC.was attempting D.have attempted13.All her energies are ________ upon children and she seems to have little time for anything else.A.guided B.aimedC.directed D.focused14.(2013·安康高三质检)________ is known to us all that the world weather is getting warmer and warmer.A.It B.WhatC.As D.Which15.The young teacher wants to help his students as much as he can, but ________,he'd better help them learn on their own.A.for one thing B.as usualC.in other words D.on the other handⅡ.完形填空(2013·西安六所重点中学高三联考)Long long ago, there was a small village. This village had a __1__ tradition. At the beginning of every year, any boy who had reached the age of majority (成年) was given land and money to build a home. The boy had to __2__ his home before winter. If his home failed to endure the cold weather in winter, the villagers could not __3__ him in any way.One __4__,Paul and Marc reached their majority. They __5__ their land and money and decided to search nearby villages for ideas on building their homes. In each village, they found the nicest __6__ and talked to the owners. Each owner gladly offered __7__.After Marc saw several homes, he __8__ the best ideas and went back to his own land. Paul, __9__,continued collecting more ideas. Soon he had so many great ideas that he began to __10__ some of them. But he always believed he could find even better ideas in the next village.Marc began building his home. He had several false starts, __11__ his home gradually rose from his land. By fall, Marc had finished his home. It wasn't perfect, but it was strong and he could __12__ it later.Paul enjoyed all the beautiful homes and __13__ with home owners. The first snow came and Paul, realizing he was running out of time, __14__ back to his land. He built the best home he could in the time he had, but it was __15__. The first winter storm destroyed his home and he froze to __16__. The villagers mourned for him.Marc __17__ the winter. Each year, Marc searched for other good ideas he could use to make his own home look better. He became a leader in the village, __18__a family, and lived a happy, content life.We all build and improve our own mental homes. It's __19__ and fun for us to search for ideas from other mental home owners, but we only improve our own mental home if we actually __20__ the best ideas.,1.A.strange B.hopefulC.literary D.cultural2.A.find B.makeC.complete D.buy3.A.help B.encourageC.scold D.persuade4.A.winter B.summerC.autumn D.spring5.A.exchanged B.receivedC.recognized D.accepted6.A.girls B.jobsC.houses D.presents7.A.rooms B.drinksC.attention D.advice8.A.expected B.gatheredC.created D.understood9.A.similarly B.finallyC.however D.furthermore10.A.forget B.believeC.replace D.doubt11.A.because B.althoughC.but D.so12.A.repair B.rebuildC.sell D.improve13.A.conversations B.achievementsC.struggles D.arguments14.A.drove B.rushedC.flew D.moved15.A.weak B.funnyC.small D.amazing16.A.blindness B.deathC.sadness D.illness17.A.experienced B.lovedC.survived D.spent18.A.brought B.earnedC.contacted D.raised19.A.slow B.easyC.dangerous D.special20.A.realize B.bringC.collect D.applyⅢ.阅读理解(2013·沈阳二中高三模拟)In eighteen seventy-seven, the American government decided to move the Nez Perce Indians from their land. The government had set up a reservation for them in Idaho. Chief Joseph did not want to leave the land. It was holy ground. It contained the bones of his father and mother.But, like his father in earlier times, Chief Joseph knew it would be hopeless to stay and defend the land. There were too few Indians to win a war against the white men.And so in June of eighteen seventy-seven, the Nez Perce left their home in the Wallowa Valley. They left quickly. They were able to take only a small part of what they owned, and just a few cattle and Appaloosa horses.When the Indians reached the Snake River, the water was very deep and ran very fast with melted snow from the mountains. Chief Joseph and his people made boats from sticks and dried animal skins to cross the river. While the Indians were busy, a group of white men came and stole some of the cattle waiting at the edge of the river.The other chiefs demanded that Joseph call a meeting. Two of the chiefs, White Bird and Toohoolhoolzote, spoke for War, but Joseph held different opinion.Some of the young men in White Bird's group were very angry. That night, they rode into thecountryside and killed eleven white persons.During all his years as chief, Joseph had tried to keep the peace. Now he saw there was no hope. Although he and his young men had taken no part in the killings, he knew that the white men would blame all of the Indians. Chief Joseph said, “I would have given my own li fe if I could have undone the killing of the white men.”Many Nez Perce fled. Chief Joseph remained, because his wife was about to have a baby. After she gave birth, he and his family joined the others in White Bird Canyon to the south.Joseph wanted to lead the people to safety in the flat lands of Montana. But the United States army quickly sent horse soldiers to follow them.They were extremely tired when they reached White Bird Canyon. An Indian — carrying a white flag — walked forward to meet them. A soldier shot him.With that shot, war between the Nez Perce and the United States began.1.Why didn't Chief Joseph want to leave the land?A.He thought the reservation in Idaho wasn't satisfying.B.He didn't want to be separated from his parents.C.He had special feeling for the land where he was living.D.He didn't want to live with the white men.2.Which of the following is TRUE?A.Before they left their home, the Nez Perce had only a few cattle and Appaloosa horses.B.Chief Joseph and his people were unwilling to cross the deep river.C.When the Indians reached the Snake River, it was very hard for them to cross it.D.While the Indians were waiting by the river, a group of white men stole some of the cattle.3.From the passage we can infer that ________.A.Chief Joseph knew it would be hopeless to defend the landB.white men often killed some IndiansC.Chief Joseph was afraid of white menD.conflicts often happened between the Indians and the white4.What might be the title of the passage?A.The story of Chief JosephB.The American Civil WarC.Chief Joseph and his childrenD.The Nez Perce Indians答案课时跟踪检测(二十六)Ⅰ.1.选C句意:“玛丽,你认为我应该去参加合唱团吗?”“为什么不呢,如果我是你的话,我肯定会参加的。

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