题型:阅读理解 题类:常考题 难易度:普通
黑龙江省双鸭山市第一中学2018-2019学年高一上学期英语第一次月考试卷
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 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 ricks.
The U.S. has countless secret swimming holes throughout most states, many of which you've likely never heard of unless you're from the area.
Havasu Falls (Arizona) | This attractive waterfall in the Grand Canyon is undoubtedly a destination spot requiring a 10-mile walk to the falls. You can take a guided tour to the falls, or make it on your own. The Havasu Falls are on the Havasupai Indian Reservation, which means you'll need to get a permit to visit — this has become increasingly difficult as more people discover this hidden place. |
Hamilton Pool (Austin) | Hamilton Pool was created when an underground river's roof fell down suddenly; exposing what is now the swimming hole and creating a 50-foot waterfall that flows over the above limestone(石灰岩). You'll have to reserve beforehand to gain entry to the Hamilton Pool Preserve. |
Chutes and Ladders (Maui) | To get to this secret swimming hole, you'll have to take a rope 40 feet down the face of a cliff, and then climb down about 8 feet of lava rock to the pool. Once there, however, you'll be glad you made the journey. The swimming hole is on the edge of the ocean — a natural pool, you could say — with a depth that invites you to jump in without crowds of people around to watch. |
Homestead Crater (Utah) | The Homestead Crater is hidden under a rock dome(圆顶) with an opening at the top that allows for sunlight and air. It was once only accessible by that top opening, but there is now easy access through a side path for visitors. Go for a swim in this beautiful mineral water spring. |
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