问题 单项选择题

以下哪项表述是错误的

A.集中供热具有节能、污染较小的优点
B.集中供热有区域锅炉房供热和热电厂供热两种形式
C.水作为载热体的优势在于热效率高,容易调节
D.以蒸汽作为载热体的优势在于传热系数高,可减少散热器传热面积,降低设备造价

答案

参考答案:C

解析:[试题解析] 水作为载热体的优势在于热效率高,能量损失小,而不是容易调节。

阅读理解

Nearly all our food comes from the soil(土地). Some of us eat meat, of course, but animals live on plants. If there were no plants, we would have no animals and no meat. So the soil is very necessary for life. The top of the ground is usually covered with grass or other plants. There may be dead leaves and dead plants on the grass. The waste matter(粪)from animals also falls on it.

All soil needs food. If we do not give it any, the plants will be weak. Farmers found that animals’ waste is the best food for the soil, but chemical fertilizers(化肥)are also very useful. The same crop(庄稼)should not be grown in the same place every year, it’s better to have a different crop. A change of crop and the use of a good fertilizer will keep the land good.

小题1:Which of the following is true?

A.All our food comes from the soil.

B.Most of our food comes from soil.

C.None of our food comes from the soil.

D.All our food comes from animals.小题2:What does the writer tell us in the first paragraph?

A.Leaves, plants, grass and waste live on each other.

B.There would be no animals without meat.

C.There would be no plants without animals.

D.People, animals, plants and soil live on each other小题3:Which is the best food for soil in the field?

A.Chemical fertilizers.

B.Plants and grass.

C.Animals’ waste.

D.Different crops.小题4:Why do we often grow a different crop in the same place every year?

A.Because we can keep the soil rich this way.

B.Because we don’t have enough land.

C.Because we want to have a different food.

D.Because we do this as a habit(习惯).

多项选择题