问题 单项选择题

关于蛋白质亚基的下列描述,哪条是正确的()。

A.一条多肽链蜷曲形成的螺旋结构

B.两条以上多肽链蜷曲形成二级结构

C.两条以上多肽链与辅基结合成蛋白质

D.每个亚基都有各自的三级结构

答案

参考答案:D

阅读理解

阅读短文,回答问题 (共5小题,每题2分,满分10分)

阅读下面短文,按要求完成相关任务。

It is said that more than four million people die each year from smoking. The number is frightening.

Yet people around the world continue to smoke. In the USA, about forty-seven-million adults smoke. This year, more than 430,000 Americans died of diseases which have something to do with smoking. The American Cancer Society (美国癌症协会) says smoking harms the body greatly. It warns that smoking even a number of cigarettes is dangerous.

(71) 戒烟是不容易的 However, doctors say you probably will live longer if you do stop smoking. You will feel better and look better. You also will protect the health of family member who breathe your smoke.

There is not one right way to stop smoking, doctors say. Anyway can help. You can take long walks or spend time in places where smoking is not allowed. Also, you can eat a small piece of fruit or vegetable instead of having a cigarette. (72) The sooner you stop smoking, the more you’ll reduce(减少) your chances of getting cancer and other diseases.

Stop smoking before smoking stops you!

小题1:How many people die from smoking each year?

                                                                    

小题2:What does the American Cancer Society say about smoking?

                                                                          

小题3:将文中划线汉语译成英语。

                                                                       

小题4:将文中划线英语译成汉语。

                                                                      

小题5:Give the title of the passage.                                         

单项选择题