Convenient ______ plastic bags are for people...

Convenient ______ plastic bags are for people, they will cause white pollution.

A. as　　 B. although

C. since　　 D. while

高二英语单项填空困难题查看答案及解析

Though plastic shopping bags are cheap and useful, they cause widespread pollution. Now, we may have an unlikely helper to help clean up our garbage — a small wax worm.

The worm’s hidden skills were discovered by accident. About two years ago, Federica Bertocchini, a developmental biologist at the Spanish National Research Council and an amateur beekeeper, was cleaning out bees’ nest that had been filled with worms. She removed the worms and put them in a plastic bag while doing the cleaning. After finishing, she went back to the room where she had left the worms, and found they had escaped from the bag. When she checked, she saw that the bag was full of holes.

Realizing she may have made an important discovery, Bertocchini teamed up with other researchers to conduct further research. They began by placing 100 worms on some plastic bags and discovered that over a 24-hour period, the worms managed to chew through 92 milligrams of plastic. The researchers make an appropriate judgment that at this rate, the group of worms could　 degrade (降解) an average-sized 5.5-gram plastic bag within a month. To rule out the possibility that chewing was causing the degradation, the researchers spread the soft wet substance inside the body of some recently dead worms on a sheet of plastic. Sure enough, even the liquid was able to eat through the material, confirming that the worms have plastic-digesting enzymes (酶).

While the news is certainly encouraging, not everyone is convinced. The Michigan State University’s Ramani Narayan believes the tiny pieces of microplastics released by the plastic-eating worms would pick up harmful substances and transport them up the food chain, causing, even more, harm to the environment and human health. Susan Selke, director of Michigan State University School of Packaging, is concerned that the worms will not be able to survive in an oxygen-free landfills where large amounts of waste material are buried under the earth.

However, Bertocchini is not planning to transport worm armies to landfills. Instead, the researcher wants to identify the enzyme that helps degrade the plastic. The researcher says, maybe we can find the molecule (分子) and produce it on an industrial level, rather than using a million worms in a plastic bag.

1.What did the experiment of using dead worms find out?

A.Worms’ chewing may cause the degradation.

B.A plastic-eating chemical exists in wax worms.

C.Dead worms are effective in dealing with plastic.

D.It takes a long time for worms to degrade plastic.

2.What is Ramani Naravan's attitude to Bertocchini's finding?

A.Objective B.Convinced C.Questioning. D.Optimistic.

3.What might Bertocchini focus her later research on?

A.The structure of plastic-degrading enzymes.

B.The use of other worms in disposing plastic.

C.Wax worms’ adaptability to the landfill environment.

D.The chance of producing wax worms on a large scale.

4.What is the best title for the text?

A.Can wax worms save the environment?

B.Wax worms have an appetite for plastic.

C.Why do wax worms have plastic-eating skills?

D.Hungry worms join the fight against plastic pollution

高二英语阅读理解中等难度题查看答案及解析

We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has-discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

Burd’s strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms (微生物). If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth. Then he added the plastic powder and let the microbes work their magic for 3 months. Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control. Sure enough, the plastic exposed to the live bacteria was 17% lighter than the control after six weeks.

The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

“Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me. One day, I got tired of it and I wanted to know what other people are doing with these plastic bags. The answer: not much. So I decided to do something myself.” Said Daniel Burd.

1.Daniel Burd won first prize at the Canada Wide Science Fair because ________.

A. he found a new kind of microorganism

B. he contributed much to environmental protection

C. he found a way to degrade plastics in shorter time

D. he could encourage microbe growth in an easier way

2. Daniel Burd exposed one plastic sample to dead bacteria to ________.

A. make the live bacteria work better      B. test how effective his method was

C. know which bacteria worked faster      D. control the temperature in the process

3.

Maintaining the required temperature takes little energy because ________.

A. plastics can get hot easily           B. microbes can produce heat themselves

C. much carbon dioxide is produced     D. the temperature can be controlled

4. Daniel Burd got his idea from ________.

A. his school textbook          B. the failure of researchers

C. his everyday work           D. the practice of other people

高二英语阅读理解中等难度题查看答案及解析

We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

Burd’s strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms(微生物)．If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth．Then he added the plastic powder and let the microbes work their magic for 3 months．Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control．Sure enough, the plastic exposed(暴露) to the live bacteria was 17% lighter than the control after six weeks.

The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

“Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me．One day, I got tired of it and I wanted to know what other people are doing with these plastic bags．The answer: not much．So I decided to do something myself.” Said Daniel Burd.

1.Daniel Burd won first prize at the Canada-Wide Science Fair because ________.

A. he found a way to degrade plastics in shorter time

B. he contributed much to environmental protection

C. he found a new kind of microorganism

D. he could encourage microbe growth in an easier way

2.Daniel Burd exposed one plastic sample to dead bacteria to ________.

A. make the live bacteria work better

B. know which bacteria worked faster

C. test how effective his method was

D. control the temperature in the process

3.Maintaining the required temperature takes little energy because ________.

A. plastics can get hot easily

B. microbes can produce heat themselves

C. much carbon dioxide is produced

D. the temperature can be controlled

4.Daniel Burd got his idea from ________.

A. his school textbook

B. the failure of researchers

C. his everyday work

D. the practice of other people

高二英语阅读理解中等难度题查看答案及解析

Plastic bags won't be allowed to be used for free in the supermarkets. They can't _________ easily, which does great harm to our environment.

A. break off                B. break in         C. break down      D. break out

高二英语单项填空简单题查看答案及解析

Come and see me whenever _______.

A. you are convenient                 B. it is convenient for you

C. you will be convenient              D. it will be convenient for you

高二英语单项填空中等难度题查看答案及解析

Come and see me whenever ____.

A. you are convenient

B. you will be convenient

C. it is convenient for you

D. it will be convenient for you

高二英语单项填空中等难度题查看答案及解析

Come and see me whenever ________．

A．it is convenient for you                   B．you will be convenient

C．you are convenient                      D．it will be convenient for you

高二英语单项填空中等难度题查看答案及解析

I will tell you the truth about plastic bags－the positive and the negative sides and provide a solution to this problem. Whether it is a shopping bag, a food bag or a trash bag, they are all made of plastic bags. Grocery store owners are very generous in using plastic bags. They place the fruit in one bag and drop the box of milk in another. Ever wonder why?

The positive side of plastic bags

Grocery stores, shopping centres, and restaurants are not thrifty in using and giving out plastic bags because they cost no more than a cent each, while a paper bag costs four cents. Plastic bags are produced so cheaply and massively（大量地）that they are used by 80% of store owners. In addition, they are light and very easy to carry and store.

The production of plastic bags has increased greatly over the last 20 years and producers of plastic bags are making large profits. However, the negative side of plastic bags is becoming well-known. More people are now getting worried that the earth is becoming a victim of the plastic bag success story.

The negative side of plastic bags

While production and consumption（消费）of plastic bags is good for business, it is not so for our Mother Earth. They have resulted in an increase in the amount of litter found floating in water or in the streets where we live.

Plastic storage bags, after usage, usually go to landfills（垃圾填埋地）as trash bags. They make the oceans poison sea animals. They give off toxins（毒素）when burned. They simply pollute the ground, air and water.

That is the true cost of plastic bags, and it looks like it is more than a cent. These are very alarming concerns and proper action needs to be taken.

1.According to Paragraph 3, plastic bag producers ________.

A．are now worried that the earth will become a victim of plastic bags

B．don’t think they have done enough to popularize plastic bags

C．have not realized the harm of plastic bags

D．have succeeded in popularizing the use of plastic bags

2.From the last three paragraphs, we learn that ________.

A．plastic bags harm the earth severely

B．most plastic bags are not made use of

C．the prices of plastic bags are reasonable

D．plastic bags are the leading polluter on the earth

3.What will the writer most probably talk about in the following paragraph?

A．How plastic bags are produced.

B．How plastic bags are used.

C．How to popularize the use of paper bags.

D．How to solve the problems caused by plastic bags.

高二英语阅读理解中等难度题查看答案及解析

In order to protect the environment，supermarkets and stores are forbidden to ______ free plastic bags to shoppers.

A．put away          B．put off            C．give off           D．give away

高二英语单项填空中等难度题查看答案及解析