额定功率相同的灯L1和L2,它们的额定电压U1>U2,下面说法正确的是[ ] A

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问题:

额定功率相同的灯L1和L2,它们的额定电压U1>U2,下面说法正确的是[ ]

A. 正常发光时,I1>I2

B. 它们的电阻,R1<R2

C. 它们串联时,P1<P2

D. 它们并联时,P1<P2

考点:电功率的计算
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The Internet has led to a huge increase in credit-card(信用卡) fraud. Your card information could even be for sale in an illegal Web site(网站).Web sites offering cheap goods and services should be regarded with care. On-line shoppers who enter their credit-card information may never receive the goods they bought. The thieves then go shopping with your card number—or sell the information over the Internet.

Computers hackers(黑客) have broken down security(安全) systems, raising questions about the safety of cardholder information. Several months ago,25 000 customers of CD Universe, an on-line music retailer(批发商),were not lucky. Their names,addresses and credit-card numbers were posted on a Web site after the retailer refused to pay US $157 828 to get back the information.

Credit-card firms are now fighting against on-line fraud. MasterCard is working on plans for Web-only credit card, with a lower credit limit. The card could be used only for shopping on-line.

However, there are a few simple steps you can take to keep from being cheated.

Ask about your credit-card firm's on-line rules: Under British law, cardholders are responsible(对……负有责任的) for the first US $78 of any fraudulent spending.

And shop only at secure sites: Send your credit-card information only if the Web site offers-advanced secure system.

  If the security is in place, a letter will appear in the bottom right-hand corner of your screen. The Web site address may also start with https://—the extra “s” stands for secure. If in doubt, give your credit-card information over the telephone.

Keep your password safe: Most online sites require a user name and password before placing an order. Treat your passwords with care.

小题1:What do most people worry about the Internet according to this passage?

A.A lot of stolen credit-cards were sold on the Internet.

B.Fraud on the Internet.

C.Many Web sites are destroyed.

D.Many illegal Web sites are on the Internet.小题2:What is the meaning of “fraud”?

A.cheating

B.sale

C.payment

D.safety小题3:How can the thieves get the information of the credit-card?

A. The customers give them the information.

B. The thieves steal the information from Web sites.

C. The customers sell the information to them.

D. Both A and B.

小题4:How many pieces of advice does the passage give to you?

A.Four.

B.Three.

C.Five.

D.Six.

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试述内照射防护的基本原则和一般方法。

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持证人(),其所在的工商行政管理局可以暂扣其《工商行政管理执法证》。

A、因涉嫌违法违纪被立案审查,尚未作出结论的

B、受到开除以外行政处分的

C、被停止履行执法职责的

D、故意损坏、涂改、复制、转借《工商行政管理执法证》,尚未造成严重后果的

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省级分公司、地市级分公司和出单分中心单证管理员,应分别按()对库存、回收实物单证进行盘点,并与单证管理系统、台账进行核对,保证账账相符、账实相符后将盘点记录归档备查。

A.周、月、季

B.季、月、周

C.季、月、月

D.季、周、月

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()的缺点是物料在运送过程中易被挤碎或压实成块,机槽和刮板磨损较快。

A.刮板输送机

B.螺旋输送机

C.胶带输送机

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