2015江西成人高考英语三级A卷试题及答案(2)

city, but they have many bullocks. And often the animals are not working. One job done by bullocks is to pump water out of the well. The animals do this by walking around and around in a circle. As they walk, they turn a heavy stick that makes the pump move. This simple technology is centuries old. Scientists thought that the same technology could be used to produce electricity. Bullocks walk in a circle only two or three times a minute. This is much too slow to produce electricity, but it can create enough power to turn a series of gears. A large gear sits next to a smaller gear. As the large gear turns, it causes the smaller gear to turn. That gear turns an even smaller one. Each gear moves faster because it is a little smaller. The smallest gear may turn extremely fast. (77)Clocks operate with gears. So do cars and so does the device invented by the Indian scientists to produce electricity.

　　According to the officials in the United Nations, the idea is being tested at several plac