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
专升本
What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s Gravity(重力) pulls it. But ev
What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s Gravity(重力) pulls it. But ev
admin
2011-03-26
25
问题
What makes it rain? Rain falls from clouds for the same reason anything falls to Earth. The Earth’s Gravity(重力) pulls it. But every cloud is made of water droplets or ice crystals. Why doesn’t rain or snow fall constantly from all clouds? The droplets or ice crystals in clouds are exceedingly small. The effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.
Droplets and ice crystals behave somewhat like dust in the air made visible in a shaft(束) of sunlight. To the casual observer, dust seems to act in a totally random fashion, moving about wildly without fixed direction. But in fact dust particles are much larger than water droplets and they finally fall. The cloud droplet of average size is only 1/2,500 inch in diameter. (78)
It is so small that it would take sixteen hours to fall half a mile in perfectly still air, and it does not fall out of moving air at all.
Only when the droplet grows to a diameter of 1/125 inch or larger can it fall form the cloud. The average raindrop contains a million times as much water as a tiny cloud droplet. The growth of a cloud droplet to a size large enough to fall out is the cause of rain.
The word "minute" in line 5 is closest in meaning to which for the following?
选项
A、Second.
B、Tiny.
C、Smooth.
D、Predictable.
答案
B
解析
从第一段第五句话中可知,云层中的雨滴很小,所以可以推断出地球对它的引力影响很小,故选B。
转载请注明原文地址:https://kaotiyun.com/show/EhqC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
InCaliforniathenumberofhomesandbusinessesthathavelostpowerare______.Thestateistryingtosolvetheproblemby_
Afterthechildrenhadbeenpunished,nobodymentionedthe______again.
Anintelligentpupilcandoadvancedwork,anditdoesnotmatter______agethechildis.
HolidaycelebrationsintheUnitedStatesoften______.NationalAdoptionmonthis______.
Independentschoolsareactuallycalled______.Whatdoestheword"ethnic"mean?
Weshoulddoeverythingpossibletoclearupthemany______(understand)betweenus.
Youcouldn’tbelievehim,forhehadonlya(an)______understandingofhistask.
WhatcanyoudotorecallyourdreamsmoreoftenandinterpretthemmoreClearly?Theexpertsofferthesesuggestions:Devel
WhatcanyoudotorecallyourdreamsmoreoftenandinterpretthemmoreClearly?Theexpertsofferthesesuggestions:Devel
Ireceivedhismother’stelephonecallateleven_____thathewasbadlyhurtinanaccidentyesterday.
随机试题
妊娠期甲状腺功能亢进症,下列检查不宜采用的是
胃蛋白酶原的激活主要依赖
女性,50岁,患耐青霉素G的金葡菌性心内膜炎,青霉素试敏阴性,既往有慢性肾盂肾炎,治疗该患者应选用
兴源公司与郭某签订钢材买卖合同,并书面约定本合同一切争议由中国国际经济贸易仲裁委员会仲裁。兴源公司支付100万元预付款后,因郭某未履约依法解除了合同。郭某一直未将预付款返还,兴源公司遂提出返还货款的仲裁请求,仲裁庭适用简易程序审理,并作出裁决,支持该请求。
我国《刑法》第357条规定:“本法所称的毒品,是指鸦片、海洛因、甲基苯丙胺(冰毒)、吗啡、大麻、可卡因以及国家规定管制的其他能够使人形成瘾癖的麻醉药品和精神药品。”据此,下列选项错误的是哪项?()
下面四个选项中,说法不正确的一项是()。
下列不是焊接工艺评定的一般过程的是()
柱钢筋绑扎每层柱第一个钢筋接头位置距楼地面高度不应小于()。
弗洛伊德强调本能和焦虑,他主张从神经衰弱里分出一个特殊的综合症,即焦虑神经症,他将焦虑分为()等类型。
Customer:Excuseme,sir.Clerk:______.Customer:I’dliketocashacheck.WouldyoupleasetellmewhichwindowshouldIgoto?
最新回复
(
0
)