2014-2015学年高二英语(人教版必修8)单元过关检测(二) Word版含答案

单元过关检测(二)(时间：120分钟，满分：150分)第Ⅰ卷第一部分阅读理解[共两节，满分60分]第一节(共15小题；每小题3分，满分45分)阅读下列短文，从每题所给的四个选项(A、B、C和D)中，选出最佳选项。

A(2014·长沙重点中学高三第四次月考) When you look at yourself in the mirror，do you ever wonder why you look the way you do?No two faces look exactly alike, making a human face as unique as a fingerprint. Genetics(遗传学) obviously play a major role—no two faces share the same DNA.But even in identical twins, there are still small differences in their appearances. So what is it that makes each face different?The answer lies in a small piece of your DNA called a “gene enhancer”，according to a study published in Science. “There are thousands of enhancers in the human genome，”study leader Axel Visel，a researcher with Berkeley Lab. US. told Disco v ery.According to Visel, these DNA pieces act like switches, turning genes on and off and therefore determining whether a certain facial feature develops in a fetus(胎儿) while it is still in the womb(子宫)．What’s interesting about gene enhancers is that they don’t have to be found anywhere close to the genes they affect. They are able to control their targets from far away, which makes them even more influential.To test how powerful these special DNA pieces are in shaping the face，researchers deleted three of the gene enhancers in mice and compared them with normal mice at 8 weeks of age. The results showed that each enhancer deletion caused a distinct set of differences in the shape of the face—for example, causing an increase or decrease in facial length or width.In fact, scientists first noticed the existence of gene enhancers long ago, but they called them “junk DNA”back then because they didn’t produce proteins and were thought to have nobiological function. But now “it’s increasingly clear that important functions are embedded in this junk” Visel told Ne w Scientist.Understanding this may help scientists learn why and how things go wrong as a fetus develops, leading to facial birth defects(缺陷) such as cleft lips.Maybe gene enhancers also play a role.【语篇解读】为何每个人都长得不一样？文章介绍了科学家们研究基因对于人们长相的影响的实验，解释了这一个问题。

1．What did Visel’s recent study uncover?A．How gene enhancers help shape the appearance of the face.B．How gene enhancers affect the growth of the fetus.C．A new cure for facial birth defects.D．The connection between gene enhancers and genetic mutations(变异)．解析：选A。

主旨大意题。

本文主要回答的是第二段提出的问题：So what is it that makes each face different？研究发现，这主要是基因增强子的功劳，所以答案是A项。

2．What does the underlined word“embed”probably mean?A．Root.B．Find.C．Absorb. D．Research.解析：选A。

词义猜测题。

根据上下文可知这句话的意思是：现在事实越来越清楚的显示出重要的功能就扎根于这种junk DNA中。

embed和root的意思相近。

故选A项。

3．Which of the following might be the best title for the passage?A．Gene Enhancers Affects Birth DefectsB．Facing Gene EnhancersC．The Power of DNA PiecesD．Gene Enhancers Determines Your Personalities解析：选B。

标题归纳题。

根据文章大意，作者主要是想介绍gene enhancer和人类面貌不同之间的关系。

所以较为合适的题目是B项。

B(2014·湖南十三校高三第一次联考)Sometimes people call each other “freaked-cat”，but have you ever thought about this expression? When a cat is frightened, its heart starts beating faster, its muscles get tense, and there are changes in the chemicals in its bloodstream. Althoughthe cat doesn’t realize this, its body is getting ready for action.If the danger continues, the animal will do one of two things. It will defend itself，or it will run away as fast as it can.Something like this also happens to people. When we are excited，angry, scared, or aroused by other emotions (feelings), our bodies go through many physical changes. Our hearts beat faster, and our muscles get tense. All of these changes make us more alert and ready to react. We, too，get ready to defend ourselves or run.Human beings, however, have a problem that animals never face.If we give way to our feelings and let them take over, we can get into trouble. Have you ever said something in anger—or hit somebody—and regretted it later? Have you ever shouted at a teacher，told somebody you were lonely, or said you were in love, and then wished later you had kept your mouth shut?It isn’t always clever to express your feelings freely.Does this mean that it’s smarter always to hide our feelings? No! If you keep feelings of anger, sadness, and bitterness hidden away or bottled up inside, your body stays tense. Physical illness can develop. It can actually be bad for your health.(It isn’t good to keep pleasant feelings inside either；all feelings need to be expressed.)Feelings that you keep all bottled up inside don’t just go away.It’s as if you bought some bananas and stuck them in a cupboard.You might not be able to see them，but before long you’d smell them.And if you opened the cupboard，chances are that you’d see little fruit flies flying all over them.They’d be rotten.You can try to treat emotions as if they were bananas in the cupboard.You can hide them and you can pretend they don’t exist，but they’ll still be around.And at last you’ll have to deal with them，just like those bananas.【语篇解读】本文主要用一只猫引出话题。