Question

All our food comes from the soil(土壤). Some of us eat meat, but animals live on plants. If there are no plants, we will have no animals and meat. So the soil is necessary for us to live.

The top of ground is usually covered with grass or other plants. Plants grow in soil, which has a dark color. This dark soil is humus. Dead leaves, dead plants and animals’ waste make it, but this takes a long time. When the humus has been made, plants can grow well in it.

All soil needs food. If we don’t give it any, the plants will be weak. 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 is better to have a different crop. A change of crop and the use of a good fertilizer will keep the land in good condition.

When the soil is dry, the wind blows it away. Sometimes heavy rain carries the humus down to a river. People should grow more and more trees and grass to stop wind from carrying the humus (腐殖土壤)away. It takes hundreds of years to make humus, and so we must save every bit of it. Without soil, where can we grow food?

1. From the text, we know people live on ___________.

A. animal B. plant

C. meat     D. soil

2. We should ___________ to keep the soil.

A. give more fertilizers

B. grow a different crop every year

C. make more humus

D. grow more trees and grass

3. We should save every bit of humus, because ___________.

A. it takes a long time to make humus

B. sometimes the wind will blow the dry soil away

C. the chemical fertilizers are expensive

D. animals waste is the best food for the soil

4.From the passage, we know that soil is ___________ to people.

A. not helpful         B. necessary

C. not important       D. harmful

Answer

1.D

2.D

3.A

4.B

【解析】

试题分析：这篇短文告诉了我们土壤的重要性。我们吃的所有食物都来源于土壤，植物生长在土壤之上。我们要注意节约土地，因为腐殖土壤的形成需要很长时间，我们要多种树和草，防止腐殖土壤被风吹走。

1.推理判断题。根据短文的开头All our food comes from the soil 以及So the soil is necessary for us to live可知，我们人类吃的所有食物都来源于土壤，土壤对于我们来说是必要的。故选D。

2.细节理解题。根据短文第四段中People should grow more and more trees and grass to stop wind from carrying the humus (腐殖土壤)away可知，人们种植越来越多的树和草是为了防止风把土壤吹走。故选D。

3.细节理解题。根据短文第四段中It takes hundreds of years to make humus, and so we must save every bit of it可知，需要花费几百年的时间，才会形成腐殖土壤，所以我们必须节约每一寸土地。故选A。

4.主旨大意题。根据全文的大意以及短文第一段的最后一句话可知，土壤对于我们人类来说是必要的，我们吃的食物来源于土壤，所有的植物都长在土壤之上。故应该选B。

考点：科普类短文阅读。