题目内容：

    There are different ways in which people try to deal with the problem of energy. One way is the greater production of common energy sources, such as coal, oil and gas. The trouble with these sources, however, is that they are not renewable.

Another way is energy conservation（节能）, which means using energy more efficiently（有效地）. In some very cold countries people build special houses to save energy. They place materials between the inside and the outside of the walls of the house to keep the cold out and the warmth in. The house is heated by the lights, the body heat of the people and the other equipment in it.

Finally, renewable energy sources are used even though they are often expensive to develop. One form of these is geothermal energy. In certain parts of the world, the temperature of the earth increases 30℃ with each kilometer down. At six kilometers, therefore, it rises to nearly two hundred degrees. To get the heat, water is pumped down into the rocks and back up to the surface. Heat from the earth is already used in certain countries.

1.From the passage we learn that oil______.

A.is quite easy to produce B.is not used most efficiently

C.is the most common energy source D.could be renewed only by new ways

2.Why are the “special houses” mentioned in the passage?

A.To keep the cold out and the warmth in.

B.To show the excellent skills of the builders.

C.To be an example of energy conservation.

D.To be heated by different sources of energy.

3.If the surface temperature is 15℃, how deep will you dig to get a temperature of 105℃?

A.One kilometer. B.Two kilometers.

C.Three kilometers. D.Four kilometers.

4.Where does the heat of the earth come from?

A.The rocks inside the earth. B.The water pumped into the earth.

C.The temperature of the earth. D.The water on the surface of the earth.