Two hydrogen atoms and one oxygen atom form a polar molecule, with a slightly positive end and a slightly negative end． [ ] A． which B． that C． it D． one 题目和参考答案——青夏教育精英家教网—

题目内容

Two hydrogen atoms and one oxygen atom form a polar molecule, ________ with a slightly positive end and a slightly negative end．

[　　]

A．

which

B．

that

C．

D．

one

答案：D

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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 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 (硅片) 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 (电池), 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 Docera at a conference of the American Chemical Society.
An 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 prorotype (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, inexpensive catalysts. These catalysts make the energy transformation (转换) 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 “giving energy to the poor”, scientists believe that the new application could be widely used in developing countries, especially in India and rural China.
【小题1】Which of the following order 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

【小题2】Which of the following statements about new artificial leaves is TRUE according to the article?

A．They are inexpensive but unstable.

B．They are as efficient at carrying out photosynthesis as natural leaves.

C．They can work only in pure water.

D．They need several catalysts to help them work efficiently.

【小题3】The aim of the scientists at MIT in developing the new artificial leaves 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

【小题4】What is the main point of the article?

A．Introduction to the history of artificial leaves.

B．An invention copying photosynthesis.

C．Giving energy to the poor.

D．A mixture of water power and solar energy.

以下是一些新闻报道的信息：

[A]. Science magazine published the study about orangutans(猩猩). The scientists collected evidence from years of observations in six areas on Borneo and Sumatra. The scientists found that the animals demonstrated a total of twenty-four signs of cultural activity. Several actions were demonstrated in some orangutan groups, but not others.

[B]. The Environmental Investigation Agency and Telapak released the report. Telapak is an environmental group based in Indonesia. The Environmental Investigation Agency operates in several countries. The two groups say Indonesia controls ten percent of the world's tropical rainforests.

[C]. Richard Sandor is the chairman of the C-C-X. He praised the companies forming the group for demonstrating leadership. He said they believe that an active way to deal with global warning helps everyone. The group said its members want to reduce costs they may face from future rules on greenhouse gas emissions. Trading credits may help businesses find the most effective methods to reduce pollution. Members also hope to improve their public image on environmental issues.

[D]. Their most detailed effort involved ninety-nine kinds of birds, insects and plants in North America and Europe. They found that the territory where these plants and animals live has moved north by an average of six kilometers every ten years. In Europe, some butterflies now live as much as one hundred kilometers to the north because of changes linked to higher temperatures.

[E]. The new report says many areas experienced unusual weather in two thousand and two. Most of Asia, for example, was warmer than usual. India had unusually high temperatures in April and May. The extremely hot weather caused hundreds of deaths. There also were extremely dry conditions across India. Parts of Africa experienced unusual heavy rains. Yet other areas in Africa had unusual dry weather.

[F]. Hydrogen is the most common element in the universe. Hydrogen is a colorless gas. On Earth, it is present in large amounts in natural gas, coal, plants and water. By weight, hydrogen produces the highest energy levels of any known fuel. When burned in an engine, hydrogen releases no harmful pollution into the environment. When powering a fuel cell, the only waste is water. However, hydrogen is difficult to store. It also burns easily.

请阅读以下与新闻信息，然后匹配与上面新闻相关的报道内容：

1. A severe ocean storm hit South Korea in August. It set a new national record for rainfall. In central Europe, more than one hundred people died in flooding caused by heavy rainfall in September. The flooding also resulted in thousands of millions of dollars in property damage. Yet large parts of North and South America had extremely dry weather.

2. One member of the Chicago Climate Exchange is American Electric Power. It's the biggest owner of electric power producers in the United States. Company officials say they hope their company's membership will demonstrate the ability of the C-C-X to grow.

3. For example, members of some groups make a kissing noise by tightening their mouths and sucking in air. Some groups use leaves to clean themselves or protect their hands from sharp objects. The scientists found that some of the animals use sticks as tools to remove insects from holes in trees. Other orangutans use leaves to crush insects or gather water.

4. Professors Parmesan and Yohe used similar methods to examine one hundred and seventy-two kinds of wildlife. They examined the timing of events in the spring, such as the appearance of flowers and the reproduction of animals. They found that these events happened an average of two days earlier than normal every ten years.

5. They say illegal operations to remove trees are causing large areas of forest to disappear. Environmental Investigation Agency director Dave Currey says the illegal operations are completely out of control.

There are two methods by which hydrogen (氢) can be used to power cars. The first way is to use hydrogen to drive the engine, in much the same way as many cars use gas. The second method is to use the reaction of hydrogen with oxygen in a battery, making the car a kind of electric one.

The dream of producing hydrogen in the car while driving along by electrolyzing（电解）water is a long way off, so we are still at the period of batteries and filling the tank with hydrogen gas. This is the difficulty for potential car users and producers. There are only sixteen hydrogen filling stations in Los Angeles and none in 99% of other cities worldwide.

Indeed, some of the big name automobile producers have pulled out of the race to put the first practical hydrogen car on the streets. Ford and GM have announced that they are pulling out in America and so has Renault in France.

However, the Japanese companies are pressing on. In fact, Honda introduced its first hydrogen fuel cell car in 1999. They are now producing second generation hydrogen car known as the FCX Clarity. Guess where they are available for sale? In only one city because of its filling stations.

Honda thinks that they could go into full-scale production of the FCX Clarity by 2020 if the world is prepared for them by then.

Then there are hydrogen-powered buses in several European cities including Amsterdam, Barcelona, Hamburg, London, Luxembourg and Madrid. Lotus, the makers of London taxis, have announced that they propose to manufacture hydrogen-powered taxis in time for the London Olympics.

So, the hydrogen vehicle is out there and the numbers will be growing fairly soon. The buses go back to their bus station, where an electrolyzing machine changes water into fuel for them to fill up on and the same will be the case for many of London’s taxis.

Unfortunately, getting fuel is not the only difficulty for the average motorist, a number of these vehicles cost about $300,000 each.

1.According to the text, hydrogen-powered buses ________.

A．can easily be filled up with gas.

B．are likely to sell well in the future.

C．are mainly used in the United States

D．won’t be used in the London Olympics

2.What does the underlined word “them” in paragraph 5 refer to?

A．Japanese companies	B．Hydrogen buses
C．The FCX Clarity	D．Filling stations

3.Where are hydrogen cars currently available for sale?

A．In Barcelona

B．In Hamburg

C．In London

D．In Los Angeles

4.We can learn from the text that ________.

A．there are sixty hydrogen filling stations all over the world

B．hydrogen vehicles fueled by water will be very expensive

C．Honda will mass-produce the FCX Clarity by 2012

D．Honda produced its first hydrogen car in 1989

The (结合)______ of one oxygen atom and two hydrogen atoms makes one water molecule.

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