报检员允许同时兼任两个或两个以上报检企业的报检工作。 ( )

In order to attract more customers, many supermarkets usually sell their goods at a good________ at weekends.

A．benefit

B．discount

C．interest

D．cost

     根据短文内容，从短文后的选项中选出能填入空白处的最佳选项。选项中有两项为多余选项。

       1   We've worked to make their streets and their schools safer, to give them something positive to do

after school and before their parents get home. We've worked to teach our children that drugs are dangerous,

illegal and wrong.

     Today, I want to talk to you about the historic opportunity we now have to protect our nation's children

from an even more deadly threat.   2   Smoking kills more people every day than AIDS, alcohol, car accidents,

murders, drugs and fires combined. Nearly 90% of those smokers lit their first cigarette before they turned

18. consider this: 3,000 children start to smoke every day illegally, and 1,000 of them will die sooner because

of it.   3   For more than five years we've worked to stop our children from smoking before they begin to try,

starting a nationwide campaign to educate them about the dangers of smoking to reduce their access to

tobacco products, and to restrict tobacco companies from advertising to young people.   4   That means if we

act now, we have it in our power to stop three million children from smoking and save a million lives as a

result. So this is an emergency that needs quick action of all of you.   5   .

A. Since I took office, I've done much to protect our children from harm.

B. This is a national tragedy(悲剧)that every American should help to prevent.

C. The quicker action we take, the fewer teen smokers there will be.

D. We have to educate them about the dangers of smoking.

E. It is smoking that is more terrible than drugs.

F. Compared with other diseases, drugs kill more people every day.

G. If we do these, we'll cut teen smoking by almost half over the next five years.

男性，27岁，体检时发现心率52次／分，律齐，心电图显示窦性心动过缓，根据运动后心电图有助于初步判断心动过缓是属于生理性还是病理性的动作是（）。

A.休息30分钟

B.短时间快速蹲立运动

C.深吸气

D.深呼气

E.左侧卧位

套筒冠义齿的缺点不包括下述哪一项（）。

A.牙体磨切量大

B.内冠金属暴露影响美观

C.反复取戴易造成外冠唇颊面颈缘瓷层损坏

D.基牙受力方式不合理

E.制作复杂，要求精度高

超声遇到小于声束直径的红细胞时即可产生散射。