问题 问答题 论述题

什么是站内轨道电路移频化?

答案

参考答案:

在移频自动闭塞区段,区间采用移频轨道电路,机车信号设备能直接接收移频信息,而站内轨道电路不能发送移频信息,当列车在站内运行时机车信号将中断工作。为了保证行车安全和提高运输效率,使机车信号在站内也能连续显示,需在站内原轨道电路的基础上进行电码化。所谓站内轨道电路电码化,指的是非电码的轨道电路能根据运行前方信号机的显示发送各种电码。对于移频轨道电路,电码化就是移频化。

阅读理解

Always forgetting your long passwords(密码)? Worried about being hacked(被攻击)?All these worries will soon become history. Scientists have found that upper-casing(大写)your password can help you reduce the chance being hacked.

Usually passwords are six letters or more.However,50 percent of people choose a common word or simple key combination for their password. The most used passwords are 123456, abcdef and abc123. In fact, if your passwords are in lower-case(小写),it will be easily hacked by a hacker. According to a study, it only takes a hacker ten minutes to hack a six-letter password which is in lower-case, but if you make the letter in upper-case, it can take up to ten hours. So if you want to make your account much safer, you should make your password upper-case. Of course, you can also add numbers or symbols to your password. Most of the time a hacker’s computer has to work for 18 days to break a password, but if you choose a nine-letter password that includes numbers and symbols, it can take a hacher’s  computer 44,530 years to break it.

小题1:Scientists have found that   your password is much safer for  

your account.

A.upper-casing

B.lower-casing

C.reducing

D.copying小题2:According to the passage,______is not one of the most used

passwords.

A.123456

B.abcdef

C.abc123

D.000000小题3:It takes a hacker___to hack a six-letter password which is in

lower—case.

A.10 minutes

B.10 hours

C.18 days

D.44,530 years小题4:The Chinese meaning of the underlined word is       

A.数字     B.符号      C.色彩       调料

小题5:What is the main idea of the passage?

A.What passwords are.

B.How a password is hacked.

C.How to make your password much safer.

D.Why hackers hack your password.

单项选择题