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 forest from which Man takes his timber is the tallest and most impressive plant community on Earth. In terms of Man’s brief
The forest from which Man takes his timber is the tallest and most impressive plant community on Earth. In terms of Man’s brief
admin
2010-01-26
57
问题
The forest from which Man takes his timber is the tallest and most impressive plant community on Earth. In terms of Man’s brief life it appears permanent and unchanging, save for the seasonal growth and fall of the leaves, but to forester it represents the climax of a long succession of events.
No wooded landscape we see today has been forest for all time. Plants have minimum requirements of temperature and moisture and, in ages past, virtually every part of Earth’s surface has at some time been either too dry or too cold for plants to survive. However, as soon as climatic conditions change in favour of plant life, a fascinating sequence of changes occurs, called a primary succession.
First to colonize the barren land are the lowly lichens, surviving on bare rock. Slowly, the acids preduced by these organisms crack the rock surface, plant debris accumulates, and mosses establish a shallow root-hold. Ferns may follow and, with short grasses and shrubs, gradually form a covering of plant life. Roots probe even deeper into the developing soil and eventually large shrubs give way to the first trees. These grow rapidly, cutting off sunlight from the smaller plants, and soon establish complete domination-closing their ranks and forming a climax community which may endure for thousands of years.
Yet even this community is not everlasting. Fire may destroy it outright and settlers may cut it down to gain land for pasture or cultivation. If the land is then abandoned, a secondary succession will take over, developing nmch faster on the more hospitable soil. Shrubs and trees are among the early invaders, their seeds carried by the wind, by birds and lodged in the coats of mammals.
For as long as it stands and thrives, the forest is a vast machine, storing energy and many elements essential for life.
What does the forest strike mankind as permanent?
选项
A、The trees are in community.
B、The forest is renewed each season.
C、Man’s life is short in comparison.
D、It is an essential part our lives.
答案
C
解析
在这篇文章的第一段的第二句话,可以找到C是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/10dK777K
0
大学英语六级
相关试题推荐
A、Becausepeoplemighthavetomigratetheresomeday.B、Becauseitisverymuchliketheearth.C、Becauseitiseasiertoexplor
Globalwarmingreferstotheaveragetemperatureoftheatmosphere,oceans,andlandmassesofEarth.Earth’ssurfacereleasess
Whatissaidabouttheactualityofthepoliticalleadershipstructure?Inthelastparagraphofthepassage,the"communityre
Accordingtothepassage,fightingagainstgreenhouseeffectsuccessfullyrequires______.Whataretheresultsoftheglobalw
Accordingtothepassage,fightingagainstgreenhouseeffectsuccessfullyrequires______.InDecember2004,Sciencedeclaredi
Acontroversyeruptedinthescientificcommunityinearly1998overtheuseofDNA(deoxyribonucleicacid)fingerprintinginCr
Theoldestandsimplestmethod,then,ofdescribingdifferencesinpersonalitywasto(36)______peopleaccordingto(37)______
随机试题
关于美金刚的叙述正确的是
下列不属于目标市场国对产品的强制性要求的是()
类风湿关节炎X线可表现为
患者,女性,30岁。因呼气性呼吸困难入院,诊断为支气管哮喘,护士为患者调节病室的相对湿度应维持在
煤气隔断装置是重要的生产装置,也是重要的安全装置。下列隔断装置属于“能单独使用作为可靠隔断装置”的是()。
下列各项中,属于会计工作管理体制的内容有()。
反映证券组合期望收益水平的总风险水平之间均衡关系的方程式是( )。
我国现阶段的人民民主专政实质上是无产阶级专政,这主要表现在()
A、Fascinating.B、Tedious.C、Interesting.D、Valueless.B女士在听到男士说他的论文主题是香蕉史时大为惊讶,并用嘲讽的口吻挖苦男士,男士随后说:不像你想象的那么无趣啦!可推测女士起初认为男士的研究很无趣,选
Overthepastdecade,Americancompanieshavetriedhardtofindwaystodiscourageseniorfromfeatheringtheirownnestsatth
最新回复
(
0
)