Question

【题目】A dam is a man-made structure built across a river. Most dams are built to control a river’s water flow, improve navigation and control flooding. However, some dams are built to produce hydro-electric power.

Hydro-electric power is produced as water passes through a dam, and into a river below. The more water that passes through a dam, the more energy is produced. Once a dam is built, a man-made lake is created behind the dam.

Electricity is produced by a kind of equipment called a turbine(水轮机). Turbines contain metal coils(线圈) surrounded by magnets(磁铁). When the magnets move round rapidly over the metal coils, electricity is produced. Turbines are located inside dams. The falling water makes the magnets go around the coils.

Dams provide clean energy, but they can also harm the environment. Species that use rivers to reproduce are often hurt by dams. In the Northwest of the US, the population of fishes has dropped from 16 million to 2.5 million since hydro-electric plants were built on the Columbia River. Dams all over the world have hurt some species.

The highest dam in the Unites States is located near Oroville, California. The Oroville Dam towers 230 meters and is more than a mile wide. This dam was built in 1968, 22 years after the Hoover Dam. The Hoover Dam, on the Nevada-Arizona border controls the Colorado river. It is 221 meters high and has 2.6 million hectare-meters of water.

The highest dam in the world is the Nurek Dam on the Vakhsh River in Tadzikistan, a country in central Asia. This dam is 300 meters tall.

【1】Which of the following statements is NOT true according to the passage?

A. Some dams are built for controlling a river’s water flow.

B. Hydro-electric power is usually produced through a dam.

C. Dams can offer energy and they are harmless to the environment.

D. Generally speaking, where there is a dam, there is a man-made lake.

【2】The third paragraph mainly tells us _____.

A. how hydro-electric power is produced

B. What a turbine is and how it works

C. how the magnets and the metal coils work

D. how the falling water passes through a turbine

【3】The dam which controls the Colorado river is ____.

A. the Oroville Dam B. the Hoover Dam

C. the Nurek Dam D. the Vakhsh Dam

Answer 1

【答案】

【1】C

【2】A

【3】B

【解析】文章向我们介绍人类建造大坝的作用和功能。

【1】细节理解题。从第一段可知A项和B项对，从第二段的最后一句可知D项对， 从第四段的第一句话,but they can also harm the environment可知C项不对。

【2】主旨大意题，第三段主要告诉了我们水电是怎样通过一些设备产生电能的，故答案为A。

【3】细节理解题。从倒数第一段的句子The Hoover Dam, on the Nevada-Arizona border controls the Colorado river.可找出答案为B。