腐蚀性场所照明配线,应采用全塑制品,所有接头处应()。A、绝缘 B、密封 C、包扎

题型:单项选择题

问题:

腐蚀性场所照明配线,应采用全塑制品,所有接头处应()。

A、绝缘

B、密封

C、包扎

D、接触牢固

考点:低压电工考试低压电工考试题库
题型:单项选择题

带支链的烷烃A(C6H14)只可能有三种一氯取代产物B、C和D,以上反应及B、D的进一步反应如下图所示。

请回答:

(1)A的名称是               ,Ⅰ的分子式是                   。

(2)写出下列反应的化学方程式:

B→F______________________________________________________________;

D→E______________________________________________________________。

(3)某一有机物X是H的同分异构体,可发生下列变化:

已知M、N均不发生银镜反应,则X的可能结构有_____________种;

写出Z可能的结构简式:_____________________________________________。

题型:单项选择题
Our Future Homes
 What kinds of homes will we live         the future? Nobody can be sure,         architects, and scientists are         new ideas now.
  Some architects are thinking about          whole cities under huge glass domes. Of course, complicated heating and        systems will be necessary to control the climate in the domes.        , there will never be any rain      snow, and the temperature will be always        .
  Perhaps everyone will live in vertical(立体的)       . High rises are so large that they can contain all the necessities of life. Since vertical cities will use        land than horizontal cities, and provide homes for more people, they will be       for small countries that have     populations.
Another idea that will be helpful to        countries (and island countries) is
the      city. Monaco has already built homes, stores, and offices         the water of the Mediterranean Sea. And a Japanese       has made a plan for constructing buildings on bridges over Tokyo Bay.
  There are some people who think we will go back to living in       . But the caves of the future will be quite      the caves of the Stone Age. Computers will control light and climate. Farms and parks will be on the land      the cave city. When people want to go to the country or to a park, a short ride in       will take them there.
小题1:
A.inB.in atC.in inD.in for
小题2:
A.andB.orC.butD.however
小题3:
A.working out B.working atC.working onD.thinking
小题4:
A.buryingB.destroyingC.foundingD.building
小题5:
A.coolingB.coldC.livingD.social
小题6:
A.So B.HoweverC.ThereforeD.Even if
小题7:
A.orB.andC.butD. with
小题8:
A.pleased B.happyC.contentD.comfortable
小题9:
A.towns B.villagesC.buildingsD.cities
小题10:
A.fewerB.moreC.largerD.less
小题11:
A.practicalB.expensiveC.unnecessaryD.useless
小题12:
A.big B.manyC.muchD.large
小题13:
A.huge B.smallC.strongD.great
小题14:
A.floatedB.floatC.floatingD.to float
小题15:
A.inB.underC.overD.on
小题16:
A.teacherB.sailorC.doctorD.architect
小题17:
A.housesB.cavesC.buildingsD.cities
小题18:
A.different from B.similar with C.equal toD.the same as
小题19:
A.under B.inC.overD.far from
小题20:
A.a busB.shipC.an elevatorD.a train
题型:单项选择题

骶管裂孔

题型:单项选择题

小儿细菌性肺炎应用抗生素治疗时,其停药时间一般是()

A.体温正常,胸片好转

B.体温正常,咳嗽消失

C.体温正常,肺部无啰音

D.体温正常后5~7天,症状基本消失后3天

E.体温正常,症状消失后5天

题型:单项选择题

超声波流量计在应用中应注意保持超声探头()。

A.清洁

B.密封性能

C.稳定性能

D.灵敏

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