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
2016-11-16
64
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 largestchemical 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/K7ud777K
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
Christinewasrecentlydiggingthrougholdboxesinherstoreroompreparingtomovetoanewhouse.Inonebox,shecameacross
What’sthebestwaytotravelashortdistanceinmostcities?
Afterthebirthofmysecondchild,Igotajobatarestaurant.Havingworkedwithanexperienced【C1】______forafewdays,Iw
Thepassageismainlytalkingabout______.Whichofthefollowingbestexplainsthemeaningoftheword"baffle"asitisused
TheEnglishauthor(writer),RichardSavage,wasoncelivinginLondoningreatpoverty.Inordertoearn(make)alittlemoney
Canyoubelieveit?There’saworldpapershortage.There’sanationalbottleshortage,andwe’rerunningoutofrawmaterialsl
Jamaicaisanislandcountry.Itisaverybeautifulandsunnyplace.Ithasgreenmountainsandwhitebeaches.Jamaicahaswarm
Mr.Duffhadseveralfarmsinthevillage.He36someworkersandmadethemworkmorethantwelvehoursa37Hedidn’tsupplyth
Ihope________roundthetouristsitesbyaspecialistguide.
随机试题
人民检察院告知犯罪嫌疑人、被告人有委托辩护人的权利的时间是自检察院收到移送审查起诉的案件材料之日起
企业成本决策的程序是
狭颅症
患者,男,35岁。3个月来间断上腹痛,有时夜间痛醒,反酸。1天前黑便1次,无呕血,但腹痛减轻,化验大便隐血强阳性。最可能的诊断是
不属于对设备制造的过程监视和测量的检验和试验阶段的是( )。
股份有限公司修改公司章程,必须经出席()的股东所持表决权的()以上通过。
若a>0,且ax=2,ay=3,则ax-y的值为()。
规定着一个国家各级各类学校教育系统包括各级各类学校的性质、任务、入学条件、修业年限及其关系的制度叫__________。
协议标记交换(MPLS)是IETF提出的第三层交换标准,下面有关MPLS的描述中,正确的是______。
Currentlyabout70,000peopleareaged100oraboveinAmerica.Leaverwasstrickenwithcancer50yearsage.
最新回复
(
0
)