Câu hỏi:

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 31 to 35.

ALTERNATIVE ENERGY SOURCES

A lot of different energy sources are used every day. Burning of fossil fuel is a main energy source. Sources other than this fossil fuel are known as alternative energy sources and there are several of them being used every day.

First of all, it is water. Water energy can be harnessed to perform work by using waterwheels.

In a hydroelectric plant the running or falling water spins a generator to create electricity.

Not only does water spin a wheel, but wind can do so as well. Windmills work in the same manner as a waterwheel. Windmills are used as wind turbines that can generate electricity.

The internal heat of the earth is another energy source. It is called geothermal energy. Geothermal energy can be used to heat homes and produce electricity.

Solar energy is often thought to be sunlight. Sunlight is full of energy. People are finding new ways to harness the power of sunlight. One major way is to trap or concentrate sunlight with the use of solar panels. This trapped sunlight can be used to heat homes and water. Also, solar cells are devices that convert sunlight into electricity.

Sources of energy other than fossil fuel are called which of the following?