学术界认为，“中国的历史时期”通常是指（）文明的时间段。 A.2000年 B.300

引起肾积水的原因有()

A．结石

B．前列腺肥大

C．肿瘤

D．晚期妊娠

E．以上都是

阅读理解。

                                                          Passwords are no safeguards

      Typing your password or credit card number into a computer is a moment's work. But if you think your

personal details disappear as soon as you hit the Return key, think again: they can sit on the computer's hard

disk for years waiting for a hacker (黑客) to take them.

      As people spend more time on the web and hackers become more experienced, the dangers of storing

personal information on computers are growing by the day, security experts say. There are some safe-guards,

such as never allowing your computer to store your passwords. But even that in no guarantee of security.

      When you type in a password, it is stored in random access memory (RAM), where it is held temporarily

until other data overwrites it or the computer is switched off. 

      But every so often, the computer copies the contents of its RAM onto hard disk, where it is easy to prey

(捕获) for a hacker, who can read it directly or design a worm to e-mail it back. The longer sensitive data

stays in RAM, the more likely it is to be copied onto the disk, where it stays until it is overwritten-which might

not happen for years.

      Tal Garfinkel and colleagues from Stanford University have created a software tool which simulates (模拟)

the workings of a complete computer system. Within the simulation, sensitive data can be tagged and then

tracked as it passes through the system. Next, Garfinkel and his team simulated computers running common

software that regularly handles passwords or secret personal information, such as Internet Explorer, the

Windows login script and Apache server software.

      In a paper to be presented, they conclude that the programs took no measures to limit the length of time

the information is kept. Some of the tested software even copied the sensitive information, obviously without

restraint (阻拦).

1. What does the passage mainly talk about? [ ]

A. It's important to set passwords to your computer.

B. Passwords help keep your personal information.

C. It's unsafe to store personal information on computers.

D. There are some safeguards for your personal information.

2. Hackers usually get others' information from _____.[ ]

A. RAM

B. the hard disk

C. a worm

D. the e-mail

3. Garfinkel and his colleagues created a software tool to _____. [ ]

A. find out how hackers steal personal information

B. protect personal information from being stolen

C. see how a complete computer system works

D. tag and track sensitive data on the computer

4. Talking about computer safety, which of the following the writer would probably suggest? [ ]

A. People should stop using computers.

B. Hackers should be heavily punished.

C. Better computer programs are needed.

D. Program developers are to blame.

我国城市空气污染主要源自汽车尾气导致的光化学烟雾。[ ]

当汽车车速无法控制时，利用专设的紧急停车道停车后，应立即（）

A.下车逃生

B.报告单位处理

C.拉紧驻车制动，检修

D.等待救援

妊娠24周子宫底高度应在

A．脐下一横指
B．脐上一横指
C．脐上三横指
D．脐与剑突之间
E．脐耻之间