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
Trees in rainforests have broad leaves. The advantage is______.
Trees in rainforests have broad leaves. The advantage is______.
admin
2010-07-06
55
问题
Trees in rainforests have broad leaves. The advantage is______.
Plants are adapted to the climate they live in for the most part. Trees in rainforests have broad leaves, shaped to encourage the heavy rain to run off the leaves. The large leaves encourage transpiration so the plants don’t overheat. In very dry climates plants may develop an ability to store water, such as the cactus, which also has its leaves reduced into tiny spines which reduce transpiration to almost nothing so its precious water is conserved. At the first sign of drought, plants close their leaf pores to prevent wilting and slowing down growth so that they need less water. Coniferous plants also have small spiky leaves so that they don’t lose too much water during the frozen winters. Grasses roll their leaves into tubes to protect their leaf pores from the drying effect of the wind. Tropical air plants have moisture sensitive plugs attached to their leaf pores which are pulled down over the pores, sealing them to hold in moisture, by the contraction of the stalks in dry weather.
Plants are affected by strong winds which make them grow thicker and more stunted stems to strengthen and prevent themselves from being blown over. A special sort of strong wood called "reaction wood" grows on the leeward side of tile wind. Plants are also susceptible to waterlogging and freezing and many plants have developed complex mechanisms and adaptations to protect themselves from disasters.
选项
A、to accept more sun light
B、to encourage the heavy rain to run off the leaves
C、to shade their roots
D、to hide their trunk
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/I1Dd777K
本试题收录于:
公共英语四级笔试题库公共英语(PETS)分类
0
公共英语四级笔试
公共英语(PETS)
相关试题推荐
YouwillhearaninterviewwithMikeRowe,hostoftheAmericanTVshowDirtyJobs.Asyoulisten,answerthequestionsorcompl
WhydoesDr.Johnsonsuggestbuildingagreenhousenearapowerstation?
WhatistheminimumnumberofprojectsrunbytheSESannually?
Howcanforeign-traineddoctorsgetapprovedfromtheEducationalCommissiontocompletearesidencyintheUS?
Thephysiciansinahospitalformthecoreofthemedicalstaff.Buttheycouldn’tprovideeffectivemedicalcaretotheirpatie
Ithasbeennecessarytoreferrepeatedlytotheeffectsofthetwoworldwarsinpromotingallkindsofinnovation.Itshouldb
Studythefollowingcartooncarefullyandwriteanessayin35minutes.Youressayshouldmeettherequirementsbelow:(1)Wr
Governmentsthroughouttheworldactontheassumptionthatthewelfareoftheirpeopledependslargelyontheeconomicstrength
Filmhaspropertiesthatsetitapartfrompainting,sculpture,novels,andplays.Itisalso,initsmostpopularandpowerful
随机试题
在美国,县政权一般实行()
下列关于生理性止血机制的描述,不正确的是
为揭示各种疾病在某人群死亡中死因顺位,应该用
腐苔不具备的特征是
雌激素生理功能有:
企业银行存款日记账与开户银行所提供的对账单核对,是通过编制银行存款余额调节表进行的。假如双方的账簿记录都没有发生差错,则调整后的存款余额()。
依据我国宪法的有关规定:省、直辖市、设区的市的人大代表受原选举单位的监督。()
已知3阶方阵A=(aij)3×3的第1行元素为:a11=1,a12=2,a13=-1.(A*)T=其中A*为A的伴随矩阵.求矩阵A.
在SQL中,涉及空值的+,-,*、/运算中,有一个操作数为空值时,结果为()。
Whatpromptedthisconversation?
最新回复
(
0
)