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 artificial leaves.

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 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 (电池), using 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 an American scientist, Nocera.

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, however, is made of cheap materials, easy to use and highly stable. In laboratory studies, Nocera showed that an artificial leaf could operate continuously for at least 45 hours.

The wonderful improvements come from Nocera’s recent discovery of several powerful new, 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 effective at carrying out photosynthesis than a natural one. Besides, the device can run in whatever water is available. This is important for some countries that don’t have access to pure water.

Hopefully, each home could have access to the new application in the future.

1.The purpose of this article is to ________.

A. introduce a new kind of device

B. ask people to do the research

C. advertise the new product

D. show the process of photosynthesis

2.Which of the following is NOT the advantages of the new leaf?

A. It’s low in cost.

B. It’s small in size.

C. It has a wonderful fuel cell.

D. It’s convenient for people to use.

3.What conclusion can be drawn from the text?

A. Nocera thought the new leaf is expensive for developing countries.

B. Villages in Africa have benefited a lot from the new invention.

C. Silicon chip can help the new leaf work more effectively.

D. The equipment doesn’t necessarily operate in pure water.

4.What’s the writer’s attitude towards the new device?

A. Negative.

B. Optimistic.

C. Doubtful.

D. Uncertain.

5.According to the text, what will take place in the future?

A. Natural leaves will take the place of artificial leaves.

B. Scientists will develop more ways to produce energy.

C. The new invention could be widely used in the future.

D. Developing countries will contribute more to the research.