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
2011-01-02
60
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℃. 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 which 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 that the water from the spring rains disappears—just a few weeks after it falls—such plants no longer need any.
The perennials have special features which 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 a short time. The small shoot system, on the other hand, considerably limits water loss by evaporation.
Another feature of many desert 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.
Grasses and flowers in the desert whose life cycles are short shows their ability to adapt to the quick disappearance of rainwater there after it fails in spring.
选项
A、Right
B、Wrong
C、Not mentioned
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/fNLd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
TheMysteriesofNazcaInthedesertofPeru,300kilometersfromLima,oneofthemostunusualartworksintheworldhasmys
OntheTrialoftheHoneyBadgerOnarecentfieldtriptotheKalahariDesert,ateamofresearcherslearnalotmoreabout
FermiProblemOnaMondaymorninginJuly,theworld’sfirstatombombexplodedinNewMexicodesert.Fortysecondslater,t
Babiescanlearnlanguageevenintheirsleep.ThethreevowelsmentionedinthisarticleareallFinnishsounds.
(Practically)allanimalscommunicateeitherthroughsoundsorthroughsoundlesscodes.
Itsoundsallwrong-drillingholesinapieceofwoodtomakeitmoreresistanttoknock.Butitworksbecausetheenergyfromt
Itsoundsallwrong-drillingholesinapieceofwoodtomakeitmoreresistanttoknock.Butitworksbecausetheenergyfromt
High-TechWarfare(战争) Today,high-techwarfareisnolongeranabstractconcept,butarealissue. Technology______(51)ta
High-TechWarfare(战争) Today,high-techwarfareisnolongeranabstractconcept,butarealissue. Technology______(51)ta
随机试题
癫痫持续状态时,首先应解决的主要矛盾是
男,23岁,农民。11月份因发热、头痛、呕吐3天为主诉入院。体检:面颈部潮红,双腋下少许出血点,化验:尿常规蛋白(+),红细胞每高倍视野3~10个,末梢血象:WBC23.0×109/L,异型淋巴10%,PLT48×109/L。住院2天后,热退但症状加重
女性,28岁,双眼睑下垂,复视2年。吡啶斯的明治疗症状一度缓解。近期出现屈颈、抬头无力,四肢疲软,此病人属于重症肌无力的哪一型
A.McBurney点压痛B.Murphy征阳性C.腹中部压痛D.脐周压痛E.下腹正中压痛94.急性阑尾炎临床表现是()。
王、张、李拟出资设立家具批发有限责任公司。现公司登记机关已经颁发了营业执照。就该公司章程效力和条款判断错误的是?
某工程的基本工作时间为10min,辅助时间为8.2%,准备与结束时间为3.89%,休息时间占8.33%,则其定额时间为()min。
民歌是人民群众在生活实践中经过广泛的口头传唱而产生和发展起来的歌曲艺术。民歌《沂蒙山小调》《嘎达梅林》《对鸟》分别属于我国哪些地区?()
个体在解决问题过程中,思维沿着许多不同的方向扩展,使观念发散到各个有关方面,最终产生多种可能的答案的认知方式称为()。
发挥人的主观能动性的前提是()
程序流程图中带有箭头的线段表示的是
最新回复
(
0
)