Question

    Smoking is harmful. But as soon as you quit the habit, everything will be OK, right? Wrong.

New research has found that even if you give up smoking, the damage it has done to your genes will stay there for a much longer time. In the research, a team of US scientists studied the blood of 16,000 people. Among them, some were smokers, some used to smoke, and the rest were non-smokers. Scientists compared their genes and found that more than 7,000 genes of smokers had changed－a number that is one-third of known human genes.

According to NBC News, both heart disease and cancer are caused by genetic changes. Some people may have had the changes when they were born, but most people get them in their day-to-day lives while doing things like smoking.

When you stop smoking, a lot of these genes will return to normal within five years.

This means your body is trying to heal (治愈) itself of the harmful effects of smoking. But the changes in some of the genes stay for longer. They can stay for as long as 30 years.It’s almost like leaving a footprint on wet cement (水泥)－it will always be there, even when you’ve walked away and when the cement becomes dry.

Although the study results may make people unhappy, there is a bright side: the findings could help scientists invent medicine to treat genetic damage caused by smoking or find ways to tell which people have heart disease or cancer risks.

1.The purpose of Paragraph 1 is to______ .

A.raise a question

B.give an example

C.make an argument

D.show the main idea of the passage

2.Most genetic changes happen because of______ .

A.people’s condition at birth B.environmental pollution

C.heart disease and cancer D.people’s bad living habit

3.The underlined word “it” in Paragraph 5 refers to______ .

A.the footprint B.the cement

C.the harmful effect D.the genetic change

4.Which of the following statements is true?

A.The findings are the fruit of more than three years’ research.

B.The findings have prevented more people from starting smoking

C.The findings help to find cures for genetic damage caused by smoking.

D.The findings offer evidence that a damaged gene can heal itself.

Answer

1.D

2.D

3.A

4.C

【解析】

本文为说明文，文章介绍了新的研究表明戒烟后对基因的影响仍然会存留一段时间。

1.

推理判断题。根据第一段Smoking is harmful．But as soon as you quit the habit，everything will be OK, right? Wrong.可知，吸烟有害，但一旦你戒烟，一切都会好起来的，对吗？错误。根据第二段New research has found that even if you give up smoking, the damage it has done to your genes will stay there for a much longer time. 新的研究表明戒烟后对基因的影响仍然会存留一段时间。由此判断出第一段的作用是介绍对文章的主题。故选D项。

2.

细节理解题。根据文章第三段中Some people may have had the changes when they were born，but most people get them in their day-to-day lives while doing things like smoking，有些人可能在出生时就有了改变，但大多数人在做吸烟之类的事情的同时，也在日常生活中得到了改变。可知，大多数遗传变化是因为人们的不良生活习惯。故选D项。

3.

词义猜测题。根据第五段中They can stay for as long as 30 years.It's almost like leaving a footprint on wet cemen——it will always be there, even when you've walked away and when the cement becomes dry可知，就像在湿水泥上留下一个脚印--，即使当你走了，水泥变干了。它会一直在那里。所以根据上下文语境可知，此处it指代上文的footprint.故选A项。

4.

细节理解题。根据最后一段Although the study results may make people unhappy，there is a bright side：the findings could help scientists invent medicine to treat genetic damage caused by smoking or find ways to tell which people have heart disease or cancer risks可知，尽管研究结果可能会让人们不高兴，但有一个光明的一面：这些发现可以帮助科学家发明药物来治疗吸烟造成的基因损伤，或者找到方法来判断哪些人患有心脏病或癌症风险。这些发现有助于找到吸烟引起的基因损伤的治疗方法。所以C选项正确。故选C项。