电弧放电时,一方面产生高热,同时还会产生弧光辐射。焊接弧光辐射主要包括()可见光线、

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问题:

电弧放电时,一方面产生高热,同时还会产生弧光辐射。焊接弧光辐射主要包括()可见光线、红外线。弧光辐射作用到人体上,造成人体组织急性或慢性的损伤。

A.氮氧化物

B.有毒气体

C.臭氧

D.紫外线

考点:金属焊接操作金属焊接操作题库
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下列哪项不是气机郁滞型呃逆的主症()

A.呃逆连声,胸胁胀闷

B.常因情志不畅而诱发或加重

C.嗳气纳减,肠鸣矢气

D.得热则减,遇寒则甚

E.舌苔薄腻,脉弦滑

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在面向对象的程序设计中,类描述的是具有相似性质的一组______。

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“In only six days I lost seven pounds of weight.”

“Two full inches in the first three days!”

These are the kinds of statements used in magazine,newspaper,radio and television ads,promising new shapes and new looks to those who buy the medicine or the device. The promoters of products say they can shape the legs,slim the face,smooth wrinkles,or in some other way to add to beauty or desirability.

Often such products are nothing more than money­making things for their promoters. The results they produce are questionable,and some are dangerous to health.

To understand how these products can be legally promoted to the public,it is necessary to understand something of the laws covering their regulation. If the product is a drug,FDA(Food and Drug Administration)can require proof under the Food,Drug,and Cosmetic Act that is safe and effective before it is put on the market. But if the product is a device,FDA has no authority to require premarketing proof of safety or effectiveness. If a product already on the market is a danger to health,FDA can request the producer or distributor to remove it from the market voluntarily,or it can take legal action,including seizure(查封)of the product.

One notable case a few years ago involved an electrical device called the Relaxacisor,which had been sold for reducing the waistline. The Relaxacisor produced electrical shocks to the body through contact pads. FDA took legal action against the distributor to stop the sale of the device on the grounds that it was dangerous to health and life.

Obviously,most of the devices on the market have never been the subject of court proceedings(法律诉讼),and new devices appear continually. Before buying,it is up to the consumer to judge the safety or effectiveness of such items.

小题1:It can be inferred that the ads mentioned in the text are________.

A.objective

B.costly

C.unreliable

D.illegal小题2:FDA can ask for the proof of safety and effectiveness of a product ________.

A.if it is a drug

B.if it is a device

C.if its consumers make complaints

D.if its distributors challenge FDA's authority小题3:The Relaxacisor is mentioned as________.

A.a product which was designed to produce electricity

B.a product whose distributor was involved in a legal case

C.a successful advertisement of a beauty product

D.an example of a quality beauty product小题4:The author intends to________.

A.make consumers aware of the promoters' false promises

B.show the weakness of the law on product safety

C.give advice on how to keep young and beautiful

D.introduce the organization of FDA

题型:单项选择题

工程建设项目盈利能力评价指标中,项目总投资收益率是指项目达产年份的( )的比率。

A.息税后利润与项目固定资产投资
B.息税前利润与项目固定资产投资
C.息税后利润与项目总投资
D.息税前利润与项目总投资

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公共政策评价效果一般可分为()。

A.直接效果

B.附带效果

C.潜在效果

D.象征性效果

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