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
A pure virus(病毒) could be kept in a bottle, just like hundreds of other chemicals. Yet, when a virus is placed on a living thing
A pure virus(病毒) could be kept in a bottle, just like hundreds of other chemicals. Yet, when a virus is placed on a living thing
admin
2018-08-10
36
问题
A pure virus(病毒) could be kept in a bottle, just like hundreds of other chemicals. Yet, when a virus is placed on a living thing, it comes to life. As long as it is on a living material, it grows.
A difficult question still remains—what is a virus? Is it living or chemical? Men of science had always thought life and not-life to be as different as black and white. With the discovery of the virus, they became aware of
a grey area
that was neither black nor white.
Until the 1930’ s, it was accepted that there was also a great difference in size between the largest chemical molecules (分子) and the smallest living things. As new and much finer filters(过滤器) were invented, men were able to measure viruses. The first virus to be measured was found to be about 100 millimicrons(毫微米) across.
The largest known chemical molecule measures only 22 millimicrons. The smallest living thing measures almost seven times that size or 150 millimicrons. When viruses were measured, they were found to range in size from 16 millimicrons to 300 millimicrons. Most were found to be larger than the largest chemical molecules and smaller than the smallest living things.
The answer to the puzzle—what is a virus? —must be that it is both living and not living. In a living cell, it is a live thing. In a bottle, it is nothing more than a chemical. We now realize that the virus is actually a link between life and not-life.
Which of the following is the smallest in size?
选项
A、Viruses.
B、New filters.
C、Living cells.
D、Chemical molecules.
答案
D
解析
推理题。题干意为“以下几个选项中,哪个是尺寸最小的?”。根据文章倒数第二段最后一句“…larger than the largest chemical molecules and smaller than the smallest living things.”可知,通过三者的比较,应该是chemical molecules最小。故D为正确答案。
转载请注明原文地址:https://kaotiyun.com/show/Lcrd777K
本试题收录于:
公共英语二级笔试题库公共英语(PETS)分类
0
公共英语二级笔试
公共英语(PETS)
相关试题推荐
Howdoesthemanlikehishaircut?
AfewdaysagoIsawainterestingprogramonTV.It76.______wasabouttheproblemofthetrafficincities.Its
It’smyfirstwritinginthenewclass.IafraidImay76.______makelotsofmistake.Butwithoutpractice,Icannever
It’smyfirstwritinginthenewclass.IafraidImay76.______makelotsofmistake.Butwithoutpractice,Icannever
Ihate______whenthere’snocomputerintheoffice.
AstudyofauniversityinShanghaihadfoundthatmanyofthestudentsthereareusingaquote(引语)fromtheItalianpoetDante
Wherearethetwospeakerstalking?
Keepin______thatallpeoplearedifferentandsomemayprogressfasterthanothers.
假定你是李明,你的美国笔友Alex将于今年四月到杭州进行为期一个月的学习。请根据以下要点给他写封信:1.表示欢迎;2.月平均气温20度左右;3.带雨伞、相机;4.祝旅行愉快。注意:1.词数100词左右;
Jimwasbornafterhiselderbrotherandsister.Hecouldlearnmanythingsfromthem.Soon,hedevelopedhisownwayofdoing
随机试题
根据《行政处罚法》的规定,下列关于行政拘留的说法正确的是()。
“一目十行”体现了注意的_______。
简述普通造影前的准备。
徐某与王某、赵某共同投资设立东盛科技发展有限公司。到20×5年年底时,公司经营管理发生严重困难,继续存续会使股东利益受到重大损失,通过其他途径也不能解决,于是徐某向人民法院提起解散公司之诉讼。对此,下列说法中正确的有()。
票据丧失的补救措施不包括()。
在市场集中度的衡量指标中,可综合反映企业数量和规模这两个决定市场结构重要方面的指标是()。
销售物流管理过程中计划和规划、策划一般包括以下阶段:调查实际、弄清问题、()、形成方案和制定政策。
自我概念有利于组织我们的思想并指导我们的社会行为,决定自我概念的有_____________、_____________、_____________、_____________、_____________和_____________。
求微分方程y"+y’-2y=(2x+1)ex-2的通解.
Thepredictabilityofourmortalityratesissomethingthathaslongpuzzledsocialscientists.Afterall,thereisnonaturalr
最新回复
(
0
)