题目内容
下面是一篇杂志文章,请将标有A~G的段落插入文章中标号1~5的合适位置,使这篇文章意义完整,结构连贯;其中有两个段落是多余的。
Soil conservation(保护)efforts protect soil from wind and water that can blow or wash it away.[1]_________ One important form of soil conservation is the use of windbreaks.Windbreaks stop the wind from blowing soil away.They also keep the wind from destroying or damaging crops.Windbreaks are barriers formed by trees and other plants with many leaves.[2]_________ Windbreaks are effective when a wall of trees and other plants blocks the wind.The windbreaks should also limit violent motions of the wind to those areas closest to the windbreak.
[3]_________ If the wall of trees and plants stops wind completely, then violent air motions will take place close to the ground.These motions cause the soil to lift up into the air where it will be blown away.[4]_________ An easy rule to remember is that windbreaks can protect areas up to ten times the height of the tallest trees in the windbreak.There should be at least two lines in each windbreak.One line should be large trees.The second line, right next to it, can be formed from shorter trees and other plants with leaves.Windbreaks not only protect land and crops from the wind.They can also provide wood products.[5]_________
a.Windbreaks seem to work best when they allow a little wind to pass through.
b.Good soil produces food crops for both humans and animals.
c.For the long term, trees will be planted throughout the area to act as windbreaks which will provide adequate protection.
d.Farmers plant windbreaks in lines around their fields.They are very important when grains such as wheat are grown.
e.Plantations are also sometimes known as “man made forests” or “tree farms”.Environmental Plantations may be established for watershed or soil protection.These are established for erosion control, landslide stabilization and windbreaks reduce carbon di oxide and increase oxygen levels in atmosphere.
f.These include wood for fuel and longer pieces for making fences.Locally grown trees and plants are best for windbreaks.
g.For this reason, a windbreak is best if it has only 60 to 80 per cent of the trees and plants needed to make a solid line.
解析:
1.b 2.d 3.a 4.g 5.f |