Question

    New research has found that even if you give up smoking, the damage it has done to your genes (基因) 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 non­smokers. Scientists compared their genes and found that more than 7, 000 genes of smokers had changed—a number that is one­third 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 day­to­day 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 function of Paragraph 1 is to ______.

A. give an example

B. arouse readers’ interest

C. make an argument

D. give the main idea of the passage

2.Most genetic changes happen because of _______.

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

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

3.The underlined word “it” in Paragraph 4 refers to _______.

A. the cement B. the footprint

C. the harmful effects 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 offer evidence that a damaged gene can heal itself.

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

Answer

1.B

2.C

3.B

4.D

【解析】

这是一篇说明文。研究发现即使已经戒烟，它对基因造成的伤害还会保留很长的时间，基因变化会使人患心脏病和癌症。

1.推理判断题。由第一段“New research has found that even if you give up smoking, the damage it has done to your genes (基因) will stay there for a much longer time.”可知，新的研究发现，即使你戒烟，它对你的基因造成的损害也会在身体里停留更长的时间。以及下文通过实验说明这一问题的和具体的影响，所以第一段点明了短文的主题，同时第1段的作用也是引起读者的兴趣。故B选项正确。

2.细节理解题。由第三段“Some people may have had the changes when they were born, but most people get them in their day­to­day lives while doing things like smoking.”可知，有些人可能在出生时基因就已经发生了变化，但大多数人的基因变化是日常生活中如吸烟所导致的。所以大多数人的基因变化是日常生活中不良的生活习惯导致的。故C选项正确。

3.词义猜测题。由第四段“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.”可知，这几乎就像在湿水泥上留下一个脚印——，即使当你走了，当水泥变干的时候，它会一直在那里。所以第4段中带下划线的“it”一词是指“足迹”。故B选项正确。

4.细节理解题。由最后段“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，这项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。所以D选项“这些发现有助于找到治疗吸烟引起的基因损伤的方法”是正确的。故D选项正确。