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

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.

1. 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

   1. A.
      cbad
   2. B.
      cabd
   3. C.
      bcad
   4. D.
      cadb
2. 2.

   Which of the following statements about new artificial leaves is TRUE according to the article?

   1. A.
      They are inexpensive but unstable.
   2. B.
      They are as efficient at carrying out photosynthesis as natural leaves.
   3. C.
      They can work only in pure water.
   4. D.
      They need several catalysts to help them work efficiently.
3. 3.

   The aim of the scientists at MIT in developing the new artificial leaves is to         .

   1. A.
      build-up more power stations in the world
   2. B.
      provide cheaper energy for developing countries
   3. C.
      offer people in developing countries access to pure water
   4. D.
      gain a deeper understanding of the photosynthesis process
4. 4.

   What is the main point of the article?

   1. A.
      Introduction to the history of artificial leaves.
   2. B.
      An invention copying photosynthesis.
   3. C.
      Giving energy to the poor.
   4. D.
      A mixture of water power and solar energy.

第二节  完形填空（共20小题；每小题1.5分，满分30分）

       阅读下面短文，从短文后所给各题的四个选项（A、B、C和D）中，选出最佳选项。

     In about 250 BC, the Greek scientist Archimedes was asked by King Hieron to

find out if his crown was__21__ gold . Archimedes thought and thought about the problem

Suddenly the answer__22__ to him when he was having a bath .

As he got into the bath .Archimedes __23__ that if he immersed (浸入)the king’s crown in a vessel __24__ to the brim (边缘) with water, it would cause some water to __25__ .If he then immersed a piece of pure gold of the same __26__ as this crown, the same amount of water would overflow if the crown was pure gold . __27__ this way , Archimedes found that the crown __28__ pure gold.

           He is believed to have rushed naked (赤裸) from his bath into the __29__shouting , “ Eureka ! ” , __30__means, “ I’ve found it !” Archimedes made many important scientific discoveries, __31__pulleys (滑轮) ,and he first explained__32__things float.

          A __33__-word code was sent from Kissinger (基辛格) to Nixon（尼克松）, “ Eureka” , meaning that the trip had been __34__.After returning from Beijing ,Kissinger and his assistant wrote a __35__ to Nixon, “We have the __36__work for you and Mao to turn a page in __37__.” On July 15 Nixon informed stunned (震惊的) television viewers of Kissinger’s __38__ trip and his own plan to visit China some time before May 1972. In October 1971, Kissinger returned to __39__, with a team of “ advance men”, to __40__ for Nixon’s own visit.

   21 A special           B true            C simple          D pure 

   22 A hit              B came           C passed          D belonged

   23 A realized          B said            C remarked        D knew 

   24 A filled            B full             C exact           D perfect

   25 A freeze           B overflow         C fall             D lose 

   26 A weight           B size             C length          D shape

   27 A On              B In              C By             D At

   28 A was not          B was hardly        C was nearly      D was almost

   29 A bathroom         B waiting-room     C bedroom        D street

   30 A when            B what             C that            D which

   31 A regarding         B supposing        C including       D considering

   32 A how             B where            C why           D when

   33 A one              B double           C three           D four

   34 A successful         B necessary         C secret         D public

   35 A letter             B report            C note           D notice

   36 A result            B ground            C full            D terrible

   37 A world            B country         C history         D century

   38 A secret            B tiring           C helpful         D dangerous

   39 A China            B U.S            C his hometown   D Greece

   40 A prepare           B wait            C send          D look

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.

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

A. cbad  B. cabd  C. bcad   D. cadb

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.

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

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.