首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The texture of the soil depends on the relative amounts of different-sized particles that combine to make up the soil. These par
The texture of the soil depends on the relative amounts of different-sized particles that combine to make up the soil. These par
admin
2013-01-15
56
问题
The texture of the soil depends on the relative amounts of different-sized particles that combine to make up the soil. These particles can be as large as stone and gravel or as small as clay.
A typical clay soil is composed of approximately 60 percent actual clay, 20 percent silt, and 20 percent sand. The particles in a sandy soil are so fine that it tends to be compact and interferes with the oxygen supply for plant roots. Water has trouble entering this impervious soil, and runoff is very common during rainfalls.
A typical light sandy soil is composed of approximately 70 percent sand, 20 percent silt, and 10 percent clay. The particles in a sandy soil are comparatively large, permitting water to enter the soil and to pass through it so quickly that it often carries nutrients with it and dries out very rapidly. The texture of sandy soils is generally very difficult to modify because huge amounts of organic material must be added.
A typical loam soil is composed of approximately 40 percent sand, 40 percent silt, and 20 percent clay, making it an ideal garden soil. It is easily worked and retains water and nutrients, which fire slowly absorbed by plant roots.
A typical adobe soil is a clay soil present in hot, dry areas of the country and is often very hard and cracked. It has all the disadvantages of a heavy clay soil and, being much drier, is more difficult to correct.
What is the author’s main purpose in this passage?
选项
A、To tell gardeners how to modify their soil.
B、To classify soil types on the basis of their composition.
C、To illustrate the effects of soil type on plant growth.
D、To show how water is absorbed by different soil.
答案
B
解析
作者写本文的目的是根据土壤的构成情况,对它们进行分类。在本文中,作者将土壤分成黏土(clay soil)、轻质沙土(light sandy oil)、肥土(loam soil)和制土砖的土 (adobe soil)。
转载请注明原文地址:https://www.kaotiyun.com/show/0K9O777K
0
考博英语
相关试题推荐
They______themselves______thepoliticianbecausetheyhopedhewouldbecomepresidentoneday.Atlasthedid.
Vitaminsareorganiccompoundsnecessaryinsmallamountsinthedietforthenormalgrowthandmaintenanceoflifeofanimals,
Vitaminsareorganiccompoundsnecessaryinsmallamountsinthedietforthenormalgrowthandmaintenanceoflifeofanimals,
Vitaminsareorganiccompoundsnecessaryinsmallamountsinthedietforthenormalgrowthandmaintenanceoflifeofanimals,
OnthemorningofSeptember11th,IboardedthetrainfromWashingtonHeightsinUpperManhattanjustasusualandwenttotheB
Ihatepeoplewho______theendofafilmthatyouhaven’tseenbefore.
OnedayI______anewspaperarticleabouttheretirementofanEnglishprofessoratanearbystatecollege.
Colorisveryimportanttomostanimalsforithelpsthemtogetalongintheworld.Color【21】tomakeananimaldifficultforit
Justasthereareoccupationsthatrequirecollegeorevenhigherdegrees,______occupationsforwhichtechnicaltrainingisne
随机试题
A.calledB.publishedC.vocallyD.feasibleE.possibleF.probablyG.primarilyH.stopI.indeedJ.con
萨迪的代表作是
简答民事权利能力的特征。
编制人工定额时,应计入工人有效工作时间的有()。
赵某日工资为160元,某年5月份单位安排其加班,且无法安排其补休,加班情况如下:(1)5月1日加班8小时;(2)5月17、18日(周一、周二)晚上加班共计4小时;(3)5月25日(周日)加班6小时。根据劳动合同法律制度的规定,5月份单位应当向赵某支付加班工
请从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性。
下列关于欧洲联盟的表述中,正确的是()
调查报告发现.区域间和国家间电子政务发展状况由于多种原因存在巨大差异,国家间经济、社会和政治发展水平的不平衡将导致这一现象长期存在。收人水平是衡量国家经济能力和发展水平的一个普遍通用指标.因此也会影响到电子政务的发展。通信基础设施、教育支持,包括信息通信技
有关游离皮片移植的下列描述,正确的是()。
Icaughta_________ofthenameofthebookbeforesheputitintothedrawer.
最新回复
(
0
)