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、They are difficult to see in the slide. B、There is an unusual number of them in the sample. C、He finds them more interesting t
A、They are difficult to see in the slide. B、There is an unusual number of them in the sample. C、He finds them more interesting t
admin
2016-10-18
71
问题
(20)This coffee can contains soil from my garden. And I prepared slide samples to show you that it is alive. This ordinary backyard dirt is crawling with microbes.(22)Microbes are not a very specific term. There are hundreds of thousands of different species called microbes. What they have in common is that we can’t see them with a naked eye. They are microscopic. Look at this slide. You should see some round cells. Those are yeasts.(21)Yeasts are fermenters. And they are necessary for making bread, beer, yogurt and so forth. Now look for an irregular shape with hairs coming out of it. That’s a mold. Molds are decomposers . and they are responsible for the decomposition mycoplastlees. You should also see some protozoa. Some protozoa, like the one causes malaria are harmful to people. A microbic that causes disease is called a pathogen. Finally you should see a lot of squiggly lines. They are bacteria—the oldest form of life on earth. Like these other microbes, bacteria are single-cells. But they are even simpler structurally because their cells do not have nuclear. So I’ve got about a teaspoon of soil in my hand here. In that teaspoon are about ten thousand protozoa, 200 thousand mold cells, a million yeasts, and probably a billion bacteria.
20. Why did the speaker take a soil sample from his garden?
21. What does the speaker imply about yeasts?
22. What does the speaker ask the class to look at during the talk?
选项
A、They are difficult to see in the slide.
B、There is an unusual number of them in the sample.
C、He finds them more interesting than other microbes.
D、They are beneficial to people.
答案
D
解析
由“Yeasts are fermenters.Andthey are necessary for making bread,beer,yo—gurt and so forth.”可知讲话者认为微生物对人类来说是有益的。
转载请注明原文地址:https://kaotiyun.com/show/HnF7777K
0
大学英语六级
相关试题推荐
A、Heneedsasuitabletypeofcalculatorforhisclass.B、Hedoesn’tknowwhenthefinanceclassbegins.C、Hedidn’tfindtheca
ShockTreatment[A]TheobjectiveofAmerica’sAffordableCareActof2010—commonlyknownasObamacare—wastoensurethatthe40m
Foreignaidisanimportantpartofinternationaleffortstoreducepoverty.TheUnitedStatesAgencyforInternationalDevelopm
A、Hedecidednottoattendsummerschool.B、Hemayhavedifficultyworkingandstudyingatthesametime.C、He’sworkinghardso
17世纪,发源于黑龙江地区的满族人统一中国,建立了清朝。清朝在建立之初遭到汉族人的激烈抵抗。1668年,清朝政府将整个东北地区封禁起来,把这个所谓的“龙兴之地”当作他们一旦失败之后的退路。1840年鸦片战争后,俄国人从北方人侵,边疆危机严重,清政府不得不放
中国的体育运动(physicalcultureandsports)经历了几千年的发展,但是直到1949年中华人民共和国成立之后体育运动才成了一项国家事业。中国发展体育运动的目的是:扩大体育宣传、增强人民体质、提高整个国家的运动技能、创造新纪录,来促进
Forthispart,youareallowed30minutestowriteashortessayentitledBigCityProblems.Youshouldwriteatleast150words
PoliceinthepopularresortcityVirginiaBeachrecentlybeganoperatingvideosurveillancecameraswithcontroversialfacerec
A、Inart.B、Ingeometry.C、Inengineering.D、Incircusperformance.A四个选项均是“In+名词”构成的介词短语,art,geometry和engineering属于学科领域,因此推测该题可
A、Theyshouldmakeseveralobservationsofthesamechild.B、Theyshouldobserveseveralchildrenatthesametime.C、Theyshoul
随机试题
售卖假货:举报维权:上门调查
患者,女,26岁。诊断为系统性红斑狼疮,双面颊和鼻梁有紫红色蝶形红斑,表面光滑,有时可见鳞屑。皮肤护理措施不正确的是()。
某肉鸭孵化和养殖场,孵出的雏鸭在育雏室3日龄即开始发病,表现为精神沉郁、厌食、眼半闭呈昏睡状,以头触地。死前有神经症状,表现为运动失调,身体倒向一侧,两脚痉挛性后蹬,全身抽搐,死时大多呈“角弓反张”姿态。对这起疫情的诊断,第一步需要进行的检查是
判断下列四个结构体系中,不是静定结构的是()。
[2012年,第58题]已知单自由度系统的振动固有频率ωn=2rad/s,若在其上分别作用幅值相同而频率为ω1=1rad/s;ω2=2rad/s;ω3=3rad/s的简谐干扰力,则此系统强迫振动的振幅为()。
梁、通风管道、排管、桥架宽度大于()时,应在其腹面以下部位增设喷头。
在深圳证券交易所,结算登记费是成交金额的()。
根据《商业银行资本管理办法(试行)》的规定,下列选项中,属于核心一级资本的有()。
下列各项中,属于流动负债的有()。
有这样一道数学题:一条小船时速20千米/小时,另一条小船时速比第一条小船快30千米。有个小学生认为第二条小船的时速是30千米/小时。这个小学生在问题解决的过程中犯错的步骤是
最新回复
(
0
)