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
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℃. 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.
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
转载请注明原文地址:https://jikaoti.com/ti/tEJsFFFM
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
TheMysteriesofNazcaInthedesertofPeru,300kilometersfromLima,oneofthemostunusualartworksintheworldhasmys
OntheTrialoftheHoneyBadgerOnarecentfieldtriptotheKalahariDesert,ateamofresearcherslearnalotmoreabout
Practicallyallspeciesofanimalscommunicateeitherthroughsoundsorthroughalargerepertoryofsoundlesscodes.
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
在考生文件夹下的“samp1.accdb”数据库文件中已建立两个表对象(名为“职工表”和“部门表”)。请按以下要求,顺序完成表的各种操作:设置表对象“职工表”的聘用时间字段默认值为系统日期。
使血压测量值相对准确的措施不包括
《最高人民法院关于审理盗窃案件具体应用法律若干问题的解释》规定:各地高级人民法院可根据本地区经济发展状况,并考虑社会治安状况,在本解释规定的数额幅度内,分别确定本地区执行“数额较大”、“数额巨大”、“数额特别巨大”的标准。依据法理学的有关原理,下列正确的表
以下企业中,属于转让定价调查应重点选择的企业有()。
每笔个人汽车贷款只能展期()次。
客户信用评级是商业银行对客户偿债能力和偿债意愿的计量和评价,反映客户违约风险的大小。()
下列关于处理意见分歧的说法中,正确的是()。
王华被学校委派到国际交流处负责外籍老师的引进和管理工作。()
Previousresearchesonmindfulnessmeditationhaveshownsomeresultsthatinfluencepeopleformanyyears.Itshowsthatmindfu
SIGG’strendyaluminumwaterbottleshavescoredalotoffreeadvertisinginrecentyears.SIGGhasbeen【67】formorethan100y
最新回复
(
0
)