问题 单项选择题

下列关于生态系统的叙述,正确的是()。

A.生态系统中生产者一定是绿色植物

B.没有分解者的生态系统,通过自我调节也可以维持生态系统的稳定性

C.在生态系统的食物链中.营养级越高的生物体型也越大

D.生态系统的能量流动是伴随物质循环而进行的

答案

参考答案:D

解析:生产者不一定是绿色植物,如硝化细菌,A错误;分解者是生态系统必不可少的成分,B错误:营养级越高,生物体型不一定越大,如昆虫比大树体型小,C错误;生态系统的能量流动是伴随物质循环而进行的,D正确。

阅读理解

阅读理解。

     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 (能源), such as coal, oil and gas. The trouble with these sources,

however, is that they are not renewable (use again).

     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 thirty

degrees centigrade with each kilometer down. At six kilometres, therefore, it rises to nearly two hundred

degrees. To get the heat, water is pumped (压;抽) down into the rocks and back up to the surface. Heat

from the earth is already used in certain countries.

1. How many ways of dealing with the energy problem are discussed in the text?

A. Two

B. Three

C. Four

D. Five.

2. The writer tells about the "special houses" because they______.

A. show the excellent skills of the builders

B. serve as an example of energy conservation

C. are heated by different sources of energy

D. are warmer than other types of houses

3. The underlined words geothermal energy in the third paragraph mean ______.

A. heat inside the earth

B. underground source

C. renewable source

D. temperature of the earth

4. At a place where the surface temperature is 15℃, how deep do you have to dig so as to

    get a temperature of 75℃?

A. One km.

B. Two km.

C. Three km.

D. Four km.

问答题 简答题