首页
登录
职称英语
[originaltext] Windbreaks are barriers formed by trees and other plants. Far
[originaltext] Windbreaks are barriers formed by trees and other plants. Far
游客
2024-02-26
7
管理
问题
Windbreaks are barriers formed by trees and other plants. Farmers plant these barriers around their fields to protect their land.
Windbreaks stop the wind from blowing soil away (33) . They also keep the wind from destroying or damaging crops. They are very important for protecting grain crops.
There have been studies done on windbreaks in parts of West Africa, for example. These found that grain harvests can be twenty percent higher in fields protected by windbreaks compared to fields without such protection (33) .
But windbreaks seem to work best when they allow some winds to pass through them (341. If the wall of trees and plants blocks the wind completely, then violent air motions will take place close to the ground. These motions will lift soil into the air where it will be blown away.
There should be at least two lines in each windbreak. one line should be large treas. The second line, right next to it, can be shorter trees and other plants with leaves. Locally grown trees and plants are best for windbreaks.
If the quality of the land is not very good, studies have shown that one kind of tree that can grow well is the white pine (35) .
Windbreaks not only protect land and crops from the wind. Surplus trees can be cut down and used to provide wood (33) .
选项
A、When there are two lines of plants in each windbreak.
B、When there is space left for some wind to go through.
C、When they are planted around crops.
D、When local green trees are planted in windbreaks.
答案
B
解析
题目问防风林什么时候效果最好。短文中提到"But windbreaks seem to work best when they allow some winds to pass through them",可见好的防风林应该留出部分空间让一些风穿过。
转载请注明原文地址:https://tihaiku.com/zcyy/3483562.html
相关试题推荐
[originaltext]Paperisoneofthemostimportantproductseverinventedby
[originaltext]Paperisoneofthemostimportantproductseverinventedby
[originaltext]Paperisoneofthemostimportantproductseverinventedby
[originaltext]AtthestartoftheMiddleAgesinEurope,therewerenoscho
[originaltext]AtthestartoftheMiddleAgesinEurope,therewerenoscho
[originaltext]M:Haveyouborrowedyourbooksyet?W:Igotmychemistrybook,
[originaltext]M:Haveyouborrowedyourbooksyet?W:Igotmychemistrybook,
[originaltext]M:Haveyouborrowedyourbooksyet?W:Igotmychemistrybook,
[originaltext]W:Hi,Peter.Ijustwonderedifyoufanciedcomingoutforacof
[originaltext]W:Hello,John,howareyoudoing?M:Notverywell.Iwasdroppe
随机试题
【B1】[br]【B4】A、lonelyB、depressedC、goodD、badD从前文来看,上网的人可能抑郁或寂寞,所以A和B均不能概括这两种
HowDeerSurviveWinterLikemostofthewildanimals,de
A.乙酰CoA羧化酶 B.己糖激酶 C.琥珀酰CoA转硫酶 D.HMGCo
不属于塞尚画作的是( )。A.《玩纸牌者》 B.《麦田上的乌鸦》 C.《有
某思想品德课老师在课堂上呈现了学生生活中情绪波动的不同画面,引导学生在情绪极为冲
投资顾问依据本公司或者其他证券公司、证券投资咨询机构发布的证券研究报告作出投资建
学生心理的发展具有的基本特征是()。A.定向性和顺序性 B.不均衡性 C.
服用中药地黄时,不能同服的饮食是A.葱、蒜、白萝卜 B.醋 C.苋菜 D.
甄选的参考依据不包括()。A.正规教育 B.工作经验 C.个人特征 D.
胃大部切除术后全麻清醒后,病人应采取的体位是() A.头低卧位 B.高半坐位
最新回复
(
0
)