下列事实中为了减小摩擦的是( ) A.下雪天,在地面上铺沙子 B.汽车轮胎上有许

题型:选择题

问题:

下列事实中为了减小摩擦的是(  )

A.下雪天,在地面上铺沙子

B.汽车轮胎上有许多凹凸不平的花纹

C.体操运动员往手上抹镁粉

D.在机器的转动部分涂润滑油

考点:增大或减小摩擦的方法
题型:选择题

The fourth round of heavy smog to hit Beijing in four weeks has sent more people to the hospital with respiratory (呼吸的) illnesses and led to calls for laws to control the pollution.

Pan Shiyi, a celebrity, said he is planning to propose a Clean Air Act to the local government. As a representative to the Beijing Municipal People's Congress, he started an online survey at 9:20 a.m. Within three hours, more than 25,000 web users, or 99 percent of total respondents (应答者) , welcomed his proposal.

They have good reasons to stand alongside Pan. The latest round of haze(雾霾)reduced visibility to under 500 meters in many parts of the city. The smog has also led to a great increase in respiratory illnesses, particularly among children and the elderly. Anxious parents and doctors almost all blame the smoggy air for the illnesses. Though most schoolchildren are home for the winter holidays, the bad air can easily move indoors. Besides, ordinary medical masks fail to provide enough protection, so some people have turned to gas masks.

The causes of the frightening smog are rather mysterious, though experts blame too much emissions (排放) and the mountains around Beijing that trap pollution in winter, unless there is enough wind to clear it away. Some critics blamed China’s top two oil firms, China National Petroleum Corp and China Petrochemical Corporation, saying the companies’ outdated production technologies produce large quantities of high-polluting gas fuel.

Meanwhile, some Beijingers have moved their brainstorming discussion to computers. If Pan’s proposal for a Clean Air Act is adopted, netizens say the new law should include items providing for “car-free days” in times of smog, higher standards for vehicle fuel, stricter limit to industrial and engine gas emissions, and more effective protection for the public.

Beijing is not the only city that has ever lost the blue sky. Five days of thick fog caused thousands of deaths in Britain in December 1952, urging the government to pass the first Clean Air Act in 1956, which introduced smokeless zones and cleaner fuels to reduce pollution. That may provide some experience for Beijing to refer to.

小题1:Why did Pan Shiyi started an online survey?

A.To know the public’s opinions on pollution

B.To tell people the danger of the smoggy weather

C.To call on people to support his proposal

D.To collect supporting evidence for his proposal小题2:What can we learn from the passage?

A.People are clear about the causes of the smoggy weather.

B.Children staying indoors will not get respiratory illnesses.

C.Smog is worse for people with lower resistance to diseases.

D.Masks can give people protection against the smoggy weather.小题3:Britain is mentioned in the last paragraph to ______.

A.suggest Beijing should learn from other countries

B.let people know many places have this problem

C.tell people the situation in Britain is worse

D.call on the government to pass Britain’s Clean Air Act小题4: What’s the best title for this passage?

A.The Use of Gas masks and Engines

B.Beijingers Call for Clean Air Act

C.Effective Protection for Blue Sky

D.The Mysterious Causes of the Scary Smog

题型:选择题

静脉全麻分为()、()、()。

题型:选择题

将工作结果与控制标准相比较,对出现的偏差进行纠正的控制类型是()

A.技术控制

B.同期控制

C.反馈控制

D.直接控制

E.前馈控制

题型:选择题

设备租赁费用中的租金的计算方法不包括( )。

A.附加率法

B.期初支付年金法

C.资金周转率法

D.期末支付年金法

题型:选择题

易产生过敏反应的局麻药是()

A、丁卡因

B、普鲁卡因

C、利多卡因

D、以上都不是

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