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 function of Paragraph 1 is to_________ .

A.introduce the topic of the passage 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.people’s bad living habit D.heart disease and cancer

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 offer evidence that a damaged gene can heal itself.

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

Answer

1.A

2.C

3.A

4.D

【解析】

抽烟有害健康，停止抽烟就会一切好起来吗？文章给出了科学的证据陈述这是一种错误的观点。

1.写作目的题。通读文章可知，第一段通过提出问题，下文具体阐述，故第一段的作用是介绍本文的话题。故选A。

2.细节理解题。根据文中的句子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.一些人可能出生时就有了这些基因的改变，但是大部分人是在日常生活中做类似抽烟时发生了基因的变化。故大部分人基因的改变发生在日常的坏习惯中，故选C。

3.词义理解题。根据划线单词it所在的句子it will always be there, even when you’ve walked away and when the cement becomes dry.它总是在那里，甚至当你走开，当水泥变干时。可知这里的it指的时上文的脚印，故选A。

4.是非判断题。根据文章最后一句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.这些发现可以帮助科学家发明药物来治疗由抽烟造成的基因破坏，或者找到方法来辨别哪些人有心脏病或者癌症的风险。可知答案D正确。