题目内容

Scientists in Britain and the United States have made a new kind of enzyme(酵素) that eats plastics(塑 料). With its help, plastics can be turned into smaller parts and go away quickly. Scientists believe that, in the future, it could solve the problem of plastic pollution.

The enzyme is able to break down PET, a form of plastic. PET was first made in the 1940s and is now widely used to make plastic bottles. It can remain in the environment for many years and pollute large areas of land and water. So it has always been a headache to deal with the waste from PET and other plastics.

The researchers made the discovery(发 现) while examining the structure of a natural enzyme in Japan. They found that the natural enzyme was helping to break down PET plastics. So, they decided to make small changes to the enzyme by adding some amino acids(氨 基 酸). It made the natural enzyme’s plastic-eating abilities work faster and better.

John McGeehan, one of the lead researchers, said, “We’ve made an improved enzyme. It’s better than the naturl one. And we are trying to make more improvements to it.” He went on, “The enzyme is not harmful to humans or animals,and it is friendly to the environment. So we are considering putting it into wider use.”

The team is now trying to make the enzyme break down PET in large quantities(大量的). “We’ll see that the plastic pollution may be stopped with this technology. However,there is still a long way to go,”John McGeehan added.

1.According to the scientists, the enzyme may solve the poblem of pollution.

A. air B. water C. light D. plastic

2.The underlined phrase “break down” in the passage probably means “ ” in Chinese.

A. 实验 B. 生产 C. 发明 D. 分解

3.Researchers discovered that a natural enzyme helped eat plastics .

A. in B. in the US C. in Japan D. in China

4.Which of the following is TRUE according to the passage?

A. The scientists are sill trying to improve the enzyme.

B. The enzyme will pollute large areas of land and water.

C. The natural enzyme woks better than the improved one.

D. The natural enzyme is harmful to humans and animals.

练习册系列答案
相关题目

Playing on the road is very dangerous，so my mother always asks me ________on it.

A. don't play B. not play C. not to play D. to play

It’s a safe bet that a robot made your car and made your computer. Pretty soon, they could be making your bed and breakfast too.

Increasingly, engineers are saying that robots are going to move out of research departments and into your home. Companies including Sony and General Electric are working on designs for small robots. Products like the Roomba, a robot that can clean floors, are flying off the shelves.

What’s behind this new robot revolution? It’s partly a matter of technology. Devices that can recognize and respond to a human voice have been developed. There are now a few different ways for robots to move around. They can walk, crawl or ride on wheels. Robots are being made smaller and smaller. They are also becoming more and more energy efficient.

A bigger part of the story is on the demand side. From the day the television remote control was invented, people around the world have searched for new ways to be lazy. Take into consideration that more and more people can afford robots, and the time seems ripe to introduce robots to the average family.

To be sure, robots that walk on two legs and talk like people are still a long way off. However, robots that do basic housework such as cleaning or gardening are sure to come out soon. One thing is certain---when these robots do come to our homes, it will change things forever.

1.According to the passage, robots can do the following things EXCEPT________.

A. cleaning floors B. making cars C. talking like people D. making computers

2.Which of the following is TRUE according to the passage?

A. Smaller robots are less energy efficient. B. Roomba has been out of date

C. People will become lazier than before. D. People’s demand contributes to new robots

3.The underlined part in the 2nd paragraph probably means________.

A. new robots will soon come into people’s homes. B. new robots can fly by themselves .

C. robot products are cheaper and cheaper D. new robots have more functions than old ones

4.What is the main idea of this passage?

A. Robots will soon be on sale B. Robots are in great demand

C. Robots are coming into our families. D. Robots help us a lot

—Has he got fruit?

—Yes. He has got apples.

A. some;any B. any;some C. any;any

As we are growing up, we really need advice from adults. Here are three people talking about their experiences.

Jasper,26, actor

You’re not alone.

Sometimes when you’re a teenager, you feel as if you’re all alone and there’s 1. you can talk to. Do you know twenty to thirty percent of teenagers in the US have a hard 2. going through the period? They feel lonely and sad. I think life is so much easier if you 3. your troubles with others. I regret that I didn’t take the advice when someone gave it to me.

Steve,27, teacher

Your teachers only want what’s best for you.

When I was in school, I never thought I’d become a teacher. I acted badly in class, and I feel 4. about that now. I love my job and I know how challenging it is, so I hope kids can show their teachers more respect(尊重). I hope kids can5. that teachers push them to do their best and not just to give them a hard time.

Anna,29, doctor

Money doesn’t grow on trees.

When I was a teenager, I never learned 6.to save money. I just spent it! My parents gave me everything I wanted, but I realize now they spent little 7. themselves. Now I wish I knew more about planning my money, and I am not the only one! It seems that today's teenagers know about money planning even less 8.me years ago. I do wish they could learn about it earlier.

The 2022 Winter Olympic Games in China. I’m sure it will be a great success.

A. hold B. will hold C. were held D. will be held

It was raining. My father asked me a raincoat.

A. take B. takes C. took D. to take

A. Sorry, I won’t. B. Well done. C. Here you are.

What will the weather be like tomorrow?

A. B. C.

违法和不良信息举报电话：027-86699610 举报邮箱：58377363@163.com

精英家教网