已知:(NH4)2CO3(s)=NH4HCO3(s)+NH3(g)△H="74.

题型:选择题

问题:

已知:(NH4)2CO3(s)=NH4HCO3(s)+NH3(g) △H="74.9" kJ·mol-1,下列说法中正确的是

A.该反应中熵变、焓变皆大于0

B.该反应是吸热反应,因此一定不能自发进行

C.碳酸盐分解反应中熵增加,因此任何条件下所有碳酸盐分解一定自发进行

D.能自发进行的反应一定是放热反应,不能自发进行的反应一定是吸热反应

考点:化学反应进行的方向
题型:选择题

女,27岁,使用宫内避孕器3年,月经基本规律,末次月经4月10日,于5月8日 * * 出血淋漓10天不净,咖啡样,伴下腹痛,不剧烈,未经任何诊治入院。

下述哪项为临床最常见的诊断()

A.早孕

B.功能性子宫出血

C.子宫内膜炎

D.异位妊娠

E.宫内避孕器异位

题型:选择题
小明从平面镜里看到镜子对电子钟示数的图象如图,这时的实际时刻是(  )

A.21:10

B.10:21

C.10:51

D.12:01

题型:选择题

雇主要求投标人开具投标保函,将招标风险转移给投标人,在风险管理中属于()。

A.财务型风险转移

B.工程保险

C.经济型风险转移

D.非保险风险转移

题型:选择题

WILD WEATHERMAN

Name: Sam Champion

Hot job: TV Weatherman

Where: WABC-TV, New York City

When you were a child, did you plan to forecast wind, rain, and snow on TV?

I wanted to be a foreign journalist.I took courses in weather science at Eastern Kentucky University, but I majored in broadcasting news.

How did you finally become a weatherman?

My first job in the early 80’s was at the local TV station in Paducah, Kentucky.I did everything from turning on the lights in the morning to writing and delivering morning news.I put together weather forecasts, and became interested in them.

Back then, how did you forecast weather?

Independent companies collected computer information that showed, for example, how a single weather system might split into snow or snow mixed with rain.The information was often opposite and the job of a weatherman was to study the information and make the best educated guess about the storm.

Has weather forecasting changed much with new technology?

Advanced computers, satellites, and Doppler radar (sound waves used to track storms) have made forecasting more exact.But we still know very little about how weather is shaped.So far, we just have theories.

Any advice for children who’d like to become weather scientists?

To me, weather is the most exciting field in the world.There are still so many more questions about weather than answers.After all, if we can’t foresee floods or hurricanes, how safe a society are we? Weather forecasting is wide open for scientists who love to solve puzzling problems.The next generation of meteorologists (weather scientists) will unlock many of Earth’s weather secrets.So get a general knowledge of Earth science, and study meteorology (weather science) in college.

Thanks, Sam.                                

1.Judging from the writing style, the text is ________.

A.a diary   B.an interview     C.a news story     D.an announcement

2.As a child, ABC-TV’s Sam Champion wanted to be a ________.

A.space scientist  B.weatherman     C.news reporter   D.meteorologist

3.Present weather forecasting technology ________.

A.has made weather report more exact than ever            

B.is still not perfect

C.hasn’t changed much in the last 50 years                           

D.both A and B

4.The study of weather science is called ________.

A. meteorology   B. forecasting    C .geography      D. earth science

题型:选择题

从时钟工作模式有()

A.跟踪模式

B.保持模式

C.自由振荡模式

D.异步模式

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