题目内容

What will power your house in the future?Nuclear,wind,or solar power?According to scientists at the Massachusetts Institute of Technology (MIT) in the US,it might be leaves — but artificial (人造的) ones.

Natural leaves are able to change sunlight and water into energy. It is known as photosynthesis (光合作用).Now researchers have found a way to imitate this seemingly simple process.

The artificial leaf developed by Daniel Nocera and his colleagues at MIT can be seen as a special silicon chip with catalysts (催化剂).Similar to natural leaves,it can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases are then stored in a fuel cell,which uses those two materials to produce electricity,located either on top of a house or beside the house.

Though the leaf is only about the shape of a poker card,scientists claimed that it is promising to be an inexpensive source of electricity in developing countries. “One can imagine villages in India and Africa not long from now purchasing an affordable basic power system based on this technology,” said Nocera at a conference of the American Chemical Society.

The artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but was too expensive and unstable for practical use. The new leaf,by contrast,is made of cheap materials,easy to use and highly stable. In laboratory studies,Nocera showed that an artificial leaf prototype (原型) could operate continuously for at least 45 hours without a drop in activity.

The wonderful improvements come from Nocera's recent discovery of several powerful,new and inexpensive catalysts. These catalysts make the energy transformation inside the leaf more efficient with water and sunlight. Right now,the new leaf is about 10 times more efficient at carrying out photosynthesis than a natural one. Besides,the device can run in whatever water is available;that is,it doesn't need pure water. This is important for some countries that don't have access to pure water.

With the goal to “make each home its own power station” and “give energy to the poor”,scientists believe that the new technology could be widely used in developing countries,especially in India and rural China.

1.Which of the following orders correctly shows how the artificial leaf is used to produce electricity?

a.artificial leaves split water into hydrogen and oxygen

b.the hydrogen and oxygen gases are stored in a fuel cell

c.the artificial leaves are put in water

d.the fuel cell uses hydrogen and oxygen to produce electricity

A. c,a,b,d B.c,b,a,d

C.b,c,a,d D.c,a,d,b

2.The purpose of the scientists at MIT in developing the new artificial leaf is to________.

A.build up more power stations in the world

B.provide cheaper energy for developing countries

C.offer people in developing countries access to pure water

D.gain a deeper understanding of the photosynthesis process

3.The main idea of this passage is ________.

A.an introduction to the history of artificial leaves

B.a mixture of water power and solar energy

C.giving energy to the poor

D.an invention copying photosynthesis

 

1.A

2.B

3.D

【解析】

试题分析:本文介绍了一项仿造叶子光合作用的发明—人工叶子的工作原理、工作性能和工作条件,可为发展中国家提供便宜的能源。

1.

2.

3.

考点:考查科普类阅读

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The connection shared by grandparents and grandchildren is something very special and despite the changing family situation, it still remains strong across generations. For most of us, our grandparents were our first best friends, the ones with whom we shared our secrets and our pain.

In majority of the cases, grandparents would have babysat their grandchildren while parents were busy working and didn't have much time for their children. Even as a kid grows up, the love and affection for grandparents never dies, and for many teens, visiting grandparents or living with them in the same house is a pleasure. Kedar Patwary, a mass communication student, says, "I often end up having long conversations with my grandfather about the evolution of Indian society and I really admire him for the patience with which he answers all my questions. "

Many teenagers feel that their parents treat them as grown-ups, while their grandparents give them much freedom.

Leela Narayanan, a grandmother. says that she loves to pamper her grandchildren and cook favorite dishes for them. She further adds that her eldest granddaughter, who is now 19, was brought up by her till she was four and the closeness they shared remains the same even now。

At times, the gap m generations plays a negative role, when grandparents find it difficult adjusting to the modern lifestyle. Technology is what works against this relationship. Youngsters' eing crazy about with gadgets leaves them with no time for their loved ones.

Maria Kutty, is a grandmother t0 12 kids. Her face lights up every time her grandchildren are mentioned. But she has one complaint. "All my children stay close to me but when they come to visit and I want to spend time with them, I can't find them anywhere. They only have time for clickety-clackety things in their hands. Sometimes they listen to loud music and talk about things I don't understand. I feel very sad when I think of all those times," she says.

1.The author uses Kedar Patwary as an example ______.

A. to show Indian society is full of perfect harmony

B. to stress all the children admire their grandparents

C. to show grandparents get on well with grandchildren

D. to indicate grandparents are all good babysitters

2.What does the underlined word "pamper" mean in the passage?

A. Spoil. B. Raise. C. Manage. D. Educate.

3.The gap generation sometimes is negative because_______.

A. grandchildren can 't fit in with modern lifestyle

B. grandparents are eager to know more technology

C. grandchildren are addicted to their digital products

D. grandparents spared no time with their grandchildren

4.How does the author develop the passage?

A. By giving example.

B. By following the order of time.

C. By making comparisons.

D. By his personal experience.

 

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1.A. seem to        B. come to    C. hope to        D. try to

2.A. design         B. promote   C. direct          D. shape

3.A. confidence  B. pressure   C. friendship   D. difficulty

4.A. opportunities   B. expectations   C. choices                D. aspects

5.A. demanding     B. deserving        C. predicting            D. presenting

6.A. comment         B. loss                    C. trouble                  D. expense

7.A. spans              B. times                C. dates                   D. ages

8.A. cases              B. fields                C. parts                     D. occasions

9.A. assessment    B. commitment    C. encouragement   D. adjustment

10.A. doubtful       B. shameful      C. harmful     D. painful

11.A. keep            B. control          C. face            D. catch

12.A. space          B. plan              C. topic         D. room

13.A. If                    B. As                 C. While       D. Unless

14.A. other than    B. rather than   C. or rather   D. or else

15.A. what                B. who                     C. where                  D. which

16.A. pass by           B. come across    C. get through          D. run over

17.A. unnecessary   B. necessary        C. impossible          D. possible

18.A. serves             B. means               C. aims                     D. attempts

19.A. opensB. appeals C. goes                     D. happens

20.A. look down on B. look back on   C. look forward to   D. look up to

 

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