(2018·*高考)Plastic­EatingWorms     Humansproducemoretha...

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(2018·*高考)

Plastic­Eating Worms

      Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills (垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.

Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics.  The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste (糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass—apparently broken down by enzymes (酶) from the worms' stomachs. Their findings were published in CurrentBiology in 2017.

      Federica Bertocchini, co­author of the study, says the worms' ability to break down their everyday food—beeswax—also allows them to break down plastic. “Wax is a complex mixture, but the basic bond in polyethylene, the carbon­carbon bond, is there as well，” she explains. “The wax worm evolved a method or system to break this bond.”

      Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown.  Is it an enzyme produced by the worm itself or by its gut microbes (肠道微生物)?

      Bertocchini agrees and hopes her team's findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process—not  simply “millions of worms thrown on top of the plastic.”

篇章导读：本文是一篇说明文。最新科学研究发现大蜡螟幼虫能利用体内的酶来分解塑料，这是一种分解塑料的新方法。

13．What can we learn about the worms in the study?

A．They take plastics as their everyday food.

B．They are newly evolved creatures.

C．They can consume plastics.

D．They wind up in landfills.

14．According to Jennifer DeBruyn, the next step of the study is to ________.

A．identify other means of the breakdown

B．find out the source of the enzyme

C．confirm the research findings

D．increase the breakdown speed

15．It can be inferred from the last paragraph that the chemical might ________.

A．help to raise worms

B．help make plastic bags

C．be used to clean the oceans

D．be produced in factories in future

16．What is the main purpose of the passage?

A．To explain a study method on worms.

B．To introduce the diet of a special worm.

C．To present a way to break down plastics.

D．To propose new means to keep eco­balance.

【回答】

13.C　细节理解题。根据第二段前两句可知，蠕虫能消耗塑料。故选C。

14.B　细节理解题。根据第四段最后两句可知，DeBruyn说，下一步将找出分解的原因。这种酶是蠕虫自身产生的，还是肠道微生物产生的？即根据Jennifer DeBruyn的说法，下一步将找出这种酶的来源。故选B。

15.D　推理判断题。根据最后一段第二句可知，她希望通过某种工业生产程序使用这种化学物质，而不是简单地“把数百万条虫子扔在塑料上”。由此可推知，将来这种化学制品可能由工厂生产。故选D。

16.C　主旨大意题。文章主要介绍了研究发现蠕虫能分解塑料，即一种分解塑料的新方法。故选C。

知识点：科普环保类阅读

题型：阅读理解