重庆市2018年中考英语试题(A卷)及答案(Word版)(6)

50．According to the passage, is one of the gardening activities.

A．watching TV B．watering flowers

C．walking dogs D．playing with phones

51．Which of the following can be the missing part in Paragraph 3?

A．Cardening will be good for your bones.

B．Cardening may help people to feel happy.

C．Gardening is a great activity to do with children.

D．Gardening can be a good way to meet neighbors.

52．The best title of the passage may be “” .

A．Outdoor Activities B．Advantages of Gardening

C．Healthy Eating Habits D．Relationships with Neighbors

C

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. Scient ists 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 an d 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 de cided to make small changes to the enzyme by adding some amino acids(氨基酸). It made the na tural 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 be tter than the naturl one. And we are trying to make more improvements to it.” He went on, “The en zyme is not harmful to humans or animals,and it is friendly to the environment. So we are consider ing 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.