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
Plants in Desert Only special plants can survive the terrible climate of a desert, for these are regions where the annual ra
Plants in Desert Only special plants can survive the terrible climate of a desert, for these are regions where the annual ra
admin
2014-05-13
34
问题
Plants in Desert
Only special plants can survive the terrible climate of a desert, for these are regions where the annual range of the soil temperature can be over 75 °C . Furthermore, during the summer there are few clouds in the sky to protect plants from the sun’ s ray. Another problem is the fact that there are frequently strong winds that drive small, sharp particles of sand into the plants, tearing and damaging them. The most difficult problem for all forms of plant life, however, is the fact that the entire annual rainfall occurs during a few days or weeks in spring.
Grasses and flowers in desert survive from one year to the next by existing through the long, hot, dry season in the form of seeds. These seeds remain inactive unless the right amount of rain falls. If no rain falls, or if insufficient rain falls, they wait until the next year, or even still the next. Another factor that helps these plants to survive is the fact that their life cycles are short. By the time the water from the spring rains disappears—just a few weeks after it falls—such plants no longer need any.
The perennials(多年生植物)have special features that enable them to survive as plants for several years. Thus, nearly all desert perennials have extensive root systems below ground and a small shoot system above ground. The large root network enables the plant to absorb as much water as possible in short time. The small shoot system, on the other hand, considerably limits water loss by evaporation(蒸发).
Another feature of many perennials is that after the rainy season they lose their leaves in preparation for the long, dry season, just as trees in wetter climates lose theirs in preparation for the winter. This reduces their water loss by evaporation during the dry season. Then, in next rainy season, they come fully alive once more, and grow new branches, leaves and flowers, just as the grasses and flowers in desert do.
The theme of the second last paragraph is why the perennials can survive as plants for several years.
选项
A、Right
B、Wrong
C、Not mentioned
答案
A
解析
倒数第二段的主题句是第一句,讲述的主要是沙漠多年生植物能生存的原因。题干表述正确,所以选择A项。
转载请注明原文地址:https://kaotiyun.com/show/ydQd777K
本试题收录于:
职称英语理工类B级题库职称英语分类
0
职称英语理工类B级
职称英语
相关试题推荐
Parkinson’sDisease1.Parkinson’sdiseaseaffectsthewayyoumove.Ithappenswhenthereisaproblemwithcertainnervec
MigrantWorkersInthepasttwentyyears,therehasbeenanincreasingtendencyforworkerstomovefromonecountrytoanot
ProlongingHumanLifeProlonginghumanlifehasincreasedthesizeofthehumanpopulation.Manypeoplealivetodaywouldha
LungCancer1Thedeathrateduetocancerofthelungshasincreasedmorethan800percentinmalesandhasmorethandoubl
LungCancerThedeathrateduetocancerofthelungshasincreasedmorethan800percentinmalesandhasmorethandoubled
NewU.S.PlanforDiseasePreventionUrgingAmericanstotakeresponsibilityfortheirhealth,HealthandHumanServicesSe
NaturalMedicinesSinceearliestdays,humanshaveusedsomekindsofmedicines.Weknowthisbecausehumanshavesurvived.
Theconferenceexploredthepossibilityofclosertradelinks.
DebateovertheUseofRenewableEnergyAmusableofRockefellerUniversityinNewYork,USsaysthekeyrenewable(可再生的)ene
TheGreatestMysteryofWhalesThewhaleisawarm-blooded,air-breathinganimal,givingbirthtoitsyoungalive,suckingt
随机试题
平素情志不畅,症见腹部结块,或左或右,走窜不定,按之略痛,脘胁不舒,嗳气频频,便艰纳呆,舌苔薄,脉弦者,其诊断是
法人在活动宗旨、经营范围方面的变化包括有()。
职务作品完成()年内,未经单位同意,作者不得许可第三人以与单位使用的相同方式使用该作品。
股权投资基金合格投资者个人金融资产包括()。I.房屋Ⅱ.汽车Ⅲ.银行存款Ⅳ.信托计划Ⅴ.期权权益
根据企业所得税的有关规定,下列关于源泉扣缴的表述中,正确的有()。
你怎样认识监狱警察权力滥用的行为?
InEnglandeveryonetalksabouttheweather.Itisthemostcommonsubject.Theystarttalkinglikethis,"Doyouthinkitwill
Theamazingsuccessofhumansasa【C1】______istheresultoftheevolutionarydevelopmentofourbrainswhichhasled,amongoth
HowmanycontinentalstateswerethereatthetimeofindependenceoftheUnitedStates?
Boy,tourismreallyisabigbusinessthesedays.It’s【B1】______.Itinvolveshotels,transportation,restaurants,shops,andth
最新回复
(
0
)