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 Nocera and his colleagues can be seen as a special silicon chip with catalysts（催化）. Similar to natural leaves. It can split water into hydrogen and oxygen when put into a bucket of water. The hydrogen and oxygen gases，the two material to produce electricity，are then stored in a fuel cell（电池），which is 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.

An artificial leaf is not a new idea. The first artificial leaf was invented in 1997 but was too expensive and unstable for practical us. The new leaf，however is made of cheap materials, easy to use and highly stable. In laboratory studies，Nocera showed at 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 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 can have access to the new application in the future.

32. 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

33. Which of the following in NOT the advantages of the new leaf?

A. It has a wonderful fuel cell.

　B. It's low in cost.

C. It's small in size.

　D. It's convenient for people to use.

34. What conclusion can be drawn from the text?

A. The new leaf is too expensive for developing countries.

B. Villages in African have benefited much from the new invention.

C. The equipment doesn't necessarily operate in pure water.

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

35. What can you infer from the last paragraph?

A. Natural leaves will be replaced by artificial ones.

B. The new invention can be widely used in the future.

C. Much remains to be done to improve the device.

D. Developing countries will contribute more to the research. 32-35.AACB