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.

 

 

    Supermarkets are trying out new computers that make shopping carts more intelligent(具备智能的). They will help shoppers find paper cups or toilet soap, and keep a record of the bill.

    The touch-screen devices(触摸屏装置) are on show at the Food Marketing Institute’s exhibition here this week, “These devices are able to create value and get you around the store quicker,” said Michael Alexander, manager of Springboard Retail Networks Inc., which makes a smart cart computer called the Concierge.

    Canadian stores will test the Concierge in July. A similar device, IBM’s “Shopping Buddy”, has recently been test-marketed at Stop & Shop stores in Massachusetts.

    Neither device tells you how many fat grams or calories are in your cart, but they will flash you with items on sale. The idea is to make it easier for people to buy, not to have second thoughts that maybe you should put something back on the shelf.

    “The whole model is driven by advertisers’ need to get in front of shoppers,” said Alexander. “They’re not watching 30-second TV ads anymore.”

    People can use a home computer to make their shopping lists. Once at the store, a shopper can use a preferred customer card to start a system(系统) that will organize the trip around the store. If you’re looking for toothpicks, you type in the word or pick it from a list, and a map will appear on the screen showing where you are and where you can find them.

    The device also keeps a record of what you buy. When you’re finished, the device figures out your bill. Then you go to the checker or place your card into a self-checkout stand and pay.

    The new computerized shopping assistants don’t come cheap. The Buddy devices will cost the average store about $160,000, and the Concierge will cost stores about $500 for each device.

1. The underlined word “they” (paragraph 1) refers to ______.

  A. supermarkets  B. shop assistants    C. shopping carts           D. shop managers

2. Which of the following is the correct order of shopping with computerized shopping carts?

  a. Start the system.                                               b. Make a shopping list.

  c. Find the things you want.                                  d. Go to a self-checkout stand.

  A. abdc                            B. bacd                        C. acbd                        D. bcad

3. We can learn from the last paragraph that ______.

  A. intelligent shopping carts cost a large sum of money

  B. the Concierge is cheaper than the Buddy devices

  C. shop assistants with computer knowledge are well paid

  D. average stores prefer the Concierge to the Buddy devices

4. What might be the most suitable title for the text?

  A. New age for supermarkets                 

B. Concierge and Shopping Buddy

  C. New computers make shopping carts smarter            

D. Touch-screen devices make shopping enjoyable

 

Supermarkets are trying out new computers that make shopping carts more intelligent(具备智能的). They will help shoppers find paper cups or toilet soap, and keep a record of the bill.

The touch-screen devices(触摸屏装置) are on show at the Food Marketing Institute’s exhibition here this week, “These devices are able to create value and get you around the store quicker,” said Michael Alexander, manager of Springboard Retail Networks Inc., which makes a smart cart computer called the Concierge.

Canadian stores will test the Concierge in July. A similar device, IBM’s “Shopping Buddy”, has recently been test-marketed at Stop & Shop stores in Massachusetts.

Neither device tells you how many fat grams or calories are in your cart, but they will flash you with items on sale. The idea is to make it easier for people to buy, not to have second thoughts that maybe you should put something back on the shelf.

“The whole model is driven by advertisers’ need to get in front of shoppers,” said Alexander. “They’re not watching 30-second TV ads anymore.”

People can use a home computer to make their shopping lists. Once at the store, a shopper can use a preferred customer card to start a system(系统) that will organize the trip around the store. If you’re looking for toothpicks, you type in the word or pick it from a list, and a map will appear on the screen showing where you are and where you can find them.

The device also keeps a record of what you buy. When you’re finished, the device figures out your bill. Then you go to the checker or place your card into a self-checkout stand and pay.

The new computerized shopping assistants don’t come cheap. The Buddy devices will cost the average store about $160,000, and the Concierge will cost stores about $500 for each device.

1. The underlined word “they” (paragraph 1) refers to ______.

A．supermarkets	B．shop assistants
C．shopping carts	D．shop managers

2. Which of the following is the correct order of shopping with computerized shopping carts?

a. Start the system.         b. Make a shopping list.

c. Find the things you want.   d. Go to a self-checkout stand.

A．abdc

B．bacd

C．acbd

D．bcad

3.We can learn from the last paragraph that ______.

A．intelligent shopping carts cost a large sum of money

B．the Concierge is cheaper than the Buddy devices

C．shop assistants with computer knowledge are well paid

D．average stores prefer the Concierge to the Buddy devices

4. What might be the most suitable title for the text?

A．New age for supermarkets

B．Concierge and Shopping Buddy

C．New computers make shopping carts smarter

D．Touch-screen devices make shopping enjoyable

 

 

    Supermarkets are trying out new computers that make shopping carts more intelligent(具备智能的). They will help shoppers find paper cups or toilet soap, and keep a record of the bill.

    The touch-screen devices(触摸屏装置) are on show at the Food Marketing Institute’s exhibition here this week, “These devices are able to create value and get you around the store quicker,” said Michael Alexander, manager of Springboard Retail Networks Inc., which makes a smart cart computer called the Concierge.

    Canadian stores will test the Concierge in July. A similar device, IBM’s “Shopping Buddy”, has recently been test-marketed at Stop & Shop stores in Massachusetts.

    Neither device tells you how many fat grams or calories are in your cart, but they will flash you with items on sale. The idea is to make it easier for people to buy, not to have second thoughts that maybe you should put something back on the shelf.

    “The whole model is driven by advertisers’ need to get in front of shoppers,” said Alexander. “They’re not watching 30-second TV ads anymore.”

    People can use a home computer to make their shopping lists. Once at the store, a shopper can use a preferred customer card to start a system(系统) that will organize the trip around the store. If you’re looking for toothpicks, you type in the word or pick it from a list, and a map will appear on the screen showing where you are and where you can find them.

    The device also keeps a record of what you buy. When you’re finished, the device figures out your bill. Then you go to the checker or place your card into a self-checkout stand and pay.

    The new computerized shopping assistants don’t come cheap. The Buddy devices will cost the average store about $160,000, and the Concierge will cost stores about $500 for each device.

1.The underlined word “they” (paragraph 1) refers to ______.

  A. supermarkets       B. shop assistants      C. shopping carts           D. shop managers

2.Which of the following is the correct order of shopping with computerized shopping carts?

  a. Start the system.                          b. Make a shopping list.

  c. Find the things you want.                  d. Go to a self-checkout stand.

  A. abdc               B. bacd             C. acbd             D. bcad

3.We can learn from the last paragraph that ______.

  A. intelligent shopping carts cost a large sum of money

  B. the Concierge is cheaper than the Buddy devices

  C. shop assistants with computer knowledge are well paid

  D. average stores prefer the Concierge to the Buddy devices

4.What might be the most suitable title for the text?

  A. New age for supermarkets                   B. Concierge and Shopping Buddy

  C. New computers make shopping carts smarter      D. Touch-screen devices make shopping enjoyable

 

    Supermarkets are trying out new computers that make shopping carts more intelligent(具备智能的). They will help shoppers find paper cups or toilet soap, and keep a record of the bill.

    The touch-screen devices(触摸屏装置) are on show at the Food Marketing Institute’s exhibition here this week, “These devices are able to create value and get you around the store quicker,” said Michael Alexander, manager of Springboard Retail Networks Inc., which makes a smart cart computer called the Concierge.

    Canadian stores will test the Concierge in July. A similar device, IBM’s “Shopping Buddy”, has recently been test-marketed at Stop & Shop stores in Massachusetts.

    Neither device tells you how many fat grams or calories are in your cart, but they will flash you with items on sale. The idea is to make it easier for people to buy, not to have second thoughts that maybe you should put something back on the shelf.

    “The whole model is driven by advertisers’ need to get in front of shoppers,” said Alexander. “They’re not watching 30-second TV ads anymore.”

    People can use a home computer to make their shopping lists. Once at the store, a shopper can use a preferred customer card to start a system(系统) that will organize the trip around the store. If you’re looking for toothpicks, you type in the word or pick it from a list, and a map will appear on the screen showing where you are and where you can find them.

    The device also keeps a record of what you buy. When you’re finished, the device figures out your bill. Then you go to the checker or place your card into a self-checkout stand and pay.

    The new computerized shopping assistants don’t come cheap. The Buddy devices will cost the average store about $160,000, and the Concierge will cost stores about $500 for each device.

1. The underlined word “they” (paragraph 1) refers to ______.

  A. supermarkets  B. shop assistants    C. shopping carts           D. shop managers

2. Which of the following is the correct order of shopping with computerized shopping carts?

  a. Start the system.                                               b. Make a shopping list.

  c. Find the things you want.                                  d. Go to a self-checkout stand.

  A. abdc                            B. bacd                        C. acbd                        D. bcad

3. We can learn from the last paragraph that ______.

  A. intelligent shopping carts cost a large sum of money

  B. the Concierge is cheaper than the Buddy devices

  C. shop assistants with computer knowledge are well paid

  D. average stores prefer the Concierge to the Buddy devices

4. What might be the most suitable title for the text?

  A. New age for supermarkets                 

B. Concierge and Shopping Buddy

  C. New computers make shopping carts smarter            

D. Touch-screen devices make shopping enjoyable