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

题干

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.

【小题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

【小题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

【小题3】The underlined word “it” in Paragraph 5 refers to__________ .

A．the footprint	B．the cement
C．the harmful effect	D．the genetic change

【小题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.

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同类题2

Of all my dreams, my least favorite is the one where I'm in a car. It always begins with me driving, but eventually I realize that for some reason I'm sitting in the back seat. I can’t keep the car under control, rushing toward the roadside until, screaming, I wake up.

This is like the passenger experience in Waymo's self-driving cars. You sit in the back seat of a vehicle and watch as the wheel turns itself above an entirely empty driving seat.

''We made you live your nightmare, '' a Waymo staff member joked after I exited one of the company's fully self-driving car, following a quick drive inside its secret testing site. Waymo, a self-driving car company, arranged these rides for 40 journalists at this site.

There were also some demonstrations(演示). We watched as a Waymo car was cut off by a speeding vehicle. Then the employees created a situation in which a pile of moving boxes fell into the street just as another car passed in the opposite direction. Throughout the day, the cars performed impressively, driving with the level of care you might take if you had a wedding cake in the back seat.

During these demonstrations, Waymo gave information about what it was planning to do with these vehicles. The company has laid out four ways that its technology could be made available to the public. But Waymo's CEO, John Krafcik, wouldn’t show which of these was likely to come to market first, or on what kind of timeline.

I can't help but admire that Waymo is succeeding in developing this technology. There are countless possibilities at play on the road. The task of programming software to react to all those situations is unimaginably complex. What a great breakthrough!

【小题1】How did the author feel about her self-driving experience in her dream?