如图所示,轻杆长1m,其两端各连接质量为1kg的小球,杆可绕距B端0.2m的轴O

题型:计算题

问题:

如图所示,轻杆长1 m,其两端各连接质量为1 kg的小球,杆可绕距B端0.2 m的轴O在竖直平面内自由转动,轻杆从静止由水平转至竖直方向,A球在最低点时的速度为4 m/s。(g取10 m/s2)求:  

(1)A小球此时对杆的作用力大小及方向;

(2)B小球此时对杆的作用力大小及方向。

考点:向心力
题型:计算题

检验用向下排空气法收集的氢气的纯度时,听到爆鸣声,这时可[ ]

A.换一支试管再收集

B.用原试管继续收集

C.直接用于实验

D.用拇指堵住试管口一会儿再收集

题型:计算题

Municipal(市政府) regulations normally ban anything from smoking in public places to parking in certain zones. But officials in the Brazilian town of Biritiba Mirim, 70km (45 miles) east of Sao Paulo, have gone far beyond that. They plan to prohibit residents from dying early because the local cemetery(墓地) has reached full capacity.

There’s no more room to bury the dead, they can’t be cremated(火化) and laws forbid a new cemetery. So the mayor has proposed a strange solution: outlaw death. Mayor Roberto Pereira says the bill is meant as a protest against federal regulations that prohibit new or expanded cemeteries in preservation areas. “They have not taken local demands into consideration”, he claims.

A 2003 decree(法令) by Brazil’s National Environment Council forbids burial grounds in protected areas. Mr. Pereira wants to build a new cemetery, but the project has been stopped because 98% of Biritiba Mirim is considered a preservation area.

Biritiba Mirim, a town of 28,000 inhabitants(居民), not only wants to prohibit residents from passing away. The bill also calls on people to take care of their health in order to avoid death. “I haven’t got a job, nor am I healthy. And now they say I can’t die. That’s ridiculous,” Amarildo do Prado, an unemployed resident said.

The city council is expected to vote on the regulation next week. “Of course the bill is laughable, illegal, and will never be approved,” said Gilson Soares de Campos, an assistant to the mayor. “But can you think of a better resolution to persuade the government to change the environmental decree that is prohibiting us from building a new cemetery?” The bill states that “offenders will be held responsible for their acts”. However, it does not say what the punishment will be.

44. What is the bill to be proposed by the officials in Biritiba Mirim?

A. Ban on smoking in public places.

B. Ban on parking in certain zones.

C. Prohibiting residents from dying early.

D. Forbidding buried grounds in preservation.

45. What can we infer from the phrase “have gone far beyond that”?

A. Officials in Biritiba Mirim have nothing of these regulations.

B. The bill to be proposed by officials in Biritiba Mirim is much too unexpected.

C. Officials in Biritiba Mirim have been to many places around the world.

D. The officials in Biritiba Mirim have built too many cemeteries in their town.

46. What’s the attitude of the mayor of Biritiba Mirim towards the federal regulations?

A. He objects to them.              

B. He gives strong backing to them.

C. He asks the residents for advice on them.    

D. He remains silent about them.

47. Which of the following is TRUE according to the article?

A. The mayor of the town wants to build a new cemetery against federal regulation.

B. The residents of the town sing the praises of the bill.

C. The government is going to change the environmental decree.

D. No better resolution of the problem has been thought out.

题型:计算题

呼叫中心的作用具体体现为()。

A.间接了解客户问题

B.架构沟通桥梁

C.改善内部管理体制

D.优化平面式服务结构

E.提高工作效率

题型:计算题

1954年,北京科技大学首届全体毕业生满怀对母校的深情和感激,向学校赠送汉白玉《钢铁摇篮》横匾,现悬挂于北京科技大学()二楼。

A.主楼

B.逸夫楼

C.教学楼

D.办公楼

题型:计算题

河南产业集聚区建设是()年开始全面推进的。

A、2007

B、2010

C、2009

D、2008

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