微机使用过程中，键盘出现部分按键失效或不灵敏，引发该故障的原因不可能是（）。 A.键

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 Website(非法网站). Websites offering cheap goods and services should be regarded with care Online shoppers who enter their credit-card information may never receive the goods they thought they bought.

The thieves then go shopping with your card number—or sell the information over the Internet. Computer hackers(黑客)have broken down security(安全) system, raising questions about the safety of card holder information.

Several months ago, 25,000 customers of a CD universe, an online music retailer(批发商), were not lucky. Their names, addresses and credit-card numbers were posted on a Website after the retailer refused to pay US $ 157,828 to get back the information.

Credit-card firms are now fighting against online fraud. Master-card is working on plans for Web only credit-card, with a lower credit limit. The card could be used only for shopping online. However , there are a few simple steps you can take to keep from being cheated.

Ask about your credit-card firm’s online rules: under British law, cardholders are responsible for the first US $ 78 of any fraudulent spending. And shop only at secure sites: send your credit-card information only if the Website offers advanced secure system.

If the security is in place, a letter will appear in the bottom right-hand corner of your screen. The Website address may also start http://--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 password with care.

小题1:The underlined word “fraud” in the first paragraph probably means ______.

A．cheating

B．sale

C．payment

D．use小题2:According to this passage most people worry about shopping on the Internet because ______.

A．a great number of stolen credit-cards are sold on the Internet every day

B．fraud on the Internet happens very often

C．many Websites break down every day

D．there are too many illegal Websites on the Internet小题3:Thieves usually get the information of the credit-card ______.

A．because many customers lost their cards

B．by paying money for people working in the information companies

C．because of the carelessness of the customers

D．by stealing the information from Websites小题4:If the passwords of your credit-cards are not probably kept, _____.

A．the bank and the shop will suffer great losses

B．you will not be able to get back your information

C．you might suffer great losses

D．the bank will answer for your loss小题5:What’s the best title of the passage?

A．How to Beat Online Credit-card Thieves

B．How to Shop on the Internet

C．Never Use Credit-card Without an Advanced Computer

D．Why Thieves Steal Credit-card Information

酶与细胞固定化

一个完整的计算机系统应当包括( )。

A．计算机与外设

B．硬件系统与软件系统

C．主机、键盘与显示器

D．系统硬件与系统软件

Ag（DDC）法（）

A．氯化物

B．砷盐

C．铁盐

D．硫酸盐

E．重金属

除氧给水装置中所加的药品是（）和（）。