首页
登录
职称英语
Only special plants can survive the terrible climate of a desert, for these a
Only special plants can survive the terrible climate of a desert, for these a
游客
2023-07-30
77
管理
问题
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 mount 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 fall--such plants no longer need ally.
The perennials(多年生植物) 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(蒸发).
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 the 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. [br] The last paragraph is mainly about ______.
选项
A、the comparison between plants in different areas
B、the growth of new leaves in the rainy season
C、water loss by evaporation in the dry season
D、the changes in the leaves of the perennials
答案
D
解析
主旨题。第四段第一句通过another feature引出本段主题句,本句中心词为 perennials和leaves,据此推断答案为D。
转载请注明原文地址:https://www.tihaiku.com/zcyy/2881973.html
相关试题推荐
[originaltext]W:Everyoneseemstobetalkingaboutclimatechangethesedays!
[originaltext]W:Everyoneseemstobetalkingaboutclimatechangethesedays!
[originaltext]Tomostforeigners,especiallythosefromtheeasternworld,su
[originaltext]Tomostforeigners,especiallythosefromtheeasternworld,su
Climate,morethananyothersinglefactor:determinesthedistributionsof
Climate,morethananyothersinglefactor:determinesthedistributionsof
E1Ninoisadisturbanceoftheworld’snormalclimatepattern.DuringElNin
E1Ninoisadisturbanceoftheworld’snormalclimatepattern.DuringElNin
TypesofClimateClimateisthecombinationoftemp
TypesofClimateClimateisthecombinationoftemp
随机试题
[originaltext]M:Hi,Cindy.W:Hello,John.M:DidyouenjoyBob’spartytheot
自杀的理论原因有哪些?
“非财政拨款结余分配”科目,核算事业单位本年度非财政拨款结余分配的情况和结果。(
公路试验检测数据报告由管理要素和技术要素构成,其中管理要素包括()。A、标题区
建设项目流动资金的分项估算法中,流动负债的构成要素一般包括()。A.应收账
阿昔洛韦又称为A.甲硝唑 B.病毒唑 C.无环鸟苷 D.环磷酰胺 E.吡
下列各项中,不属于资产负债表日后非调整事项的是:A.资产负债表日后发生重大诉讼
企业事业单位和其他生产经营者,为改善环境,依照有关规定转产、搬迁、关闭的,人民政
根据票据法律制度的规定,下列票据行为人中,其签章不符合票据法规定可导致票据无效的
对建筑工程一切险而言,保险人对( )造成的物质损失不承担赔偿责任。A、自然灾害
最新回复
(
0
)