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Plastic remains one of the most-used materials for making many things we use in our everyday lives. Things made of plastic can be very strong and last a long time. They also do well in extreme heat and cold. Plastic is also much lighter than metal and can easily be formed into different shapes. But plastic can take hundreds of years to break down on their own. Very few kinds are highly recyclable.

But a team of researchers working at the U.S. Department of Energy says it has created a kind of plastic that could lead to products that are 100 percent recyclable. The researchers say the new material is a plastic polymer called polydiketoenamine, or PDK. The team reports that the material can be broken down in parts at the molecular level.

It can then be built up again to form plastics of different shapes, colors and more. The researchers say this process can be repeated over and over again—without the plastic material losing any performance or quality.

“Most plastics were never made to be recycled," lead researcher Peter Christensen said in a statement. Christensen works at Berkeley Lab's Molecular Foundry center. “But we have discovered a new way to assemble plastics that takes recycling into consideration from a molecular perspective.”

1.Plastic has some advantages EXCEPT _______.

A being lighter than metal

B being formed into many kinds of shapes

C lasting a lot of time

D being recycled at any time

解析：选D。细节理解题。根据第一段Things made of plastic can be very strong and last a long time. They also do well in extreme heat and cold. Plastic is also much lighter than metal and can easily be formed into different shapes. But plastic can take hundreds of years to break down on their own. 可知，塑料需要数百年时间才能自行降解，故选D。

2.What does the second paragraph mainly talk about?

A The researchers invented a new kind of plastic.

B The researchers work very hard on studying plastic.

C How the researchers take recycling plastic into consideration.

D Why most plastics were never made to be recycled.

解析：选A。主旨大意题。根据第二段But a team of researchers working at the U.S. Department of Energy says it has created a kind of plastic that could lead to products that are 100 percent recyclable.可知，研究团队研制出一种可以生产出100%可回收的新的塑料产品，故选A。

3.Which of the following is NOT true about the new plastic?

A It could lead to products that are 100 percent recyclable.

B It is a plastic polymer that can be broken down at the molecular level.

C It can be built up again to form plastics of different shapes and colors.

D It can lose some performance or quality in the process of assembling.

解析：选D。推理判断题。根据第三段The researchers say this process can be repeated over and over again—without the plastic material losing any performance or quality.可知，新型塑料在合成的过程中不会失去性能或质量，故选D。

4.In which section of a newspaper can we read this passage?

A Business.

B Education.

C Technology.

D Art.

解析：选C。推理判断题。本文介绍了一种新型的塑料，属于新的科技发明，可以在科技板块里读到这篇文章，故选C。