Let me try a wild guess：the system of passwords you use on the Internet- for accessing online banking，e-mail，shopping sites，and Renren accounts- is a mess（一团糟）．
   You know perfectly well what you ought to be doing for each site you visit，you should be choosing a different，complex sequence of letters，numbers and symbols，and then memorizing it． （That's the first rule of the common knowledge on passwords：never，ever write them down．） But you don't do this，because it's hard for you to remember so many numbers．
   So instead，you use the same familiar words for every site-your dog's name，the name of your street-by adding"123"at the end．Or maybe you do try to follow the rules，and if you're probably getting locked out of your bank account，you began trying to remember the answers to various security questions． （"What was your favourite sport as a child？"）
   A recent security breach （安全漏洞） at Yahoo showed that thousands of users' passwords were either "password"， "welcome"， " 123456"or"ninja"．People choose terrible passwords even when more is in danger than their savings．
   Password hacking takes many different forms．This is where the length of your password makes an almost unbelievable difference．For a hacker with the computing power to make 1，000 guesses per second，a five-letter，purely random，all-lower-case password，such as "fpqzy"，would take three and three quarters hours to crack．Increase the number of letters to 20，and the cracking time increases it's 6.5 thousand trillion centuries．
   If you think you've got a clever system for coming up with passwords，the chances are that hackers are already familiar with it．The least hackable password，then，would be a long string of completely random letters，numbers，spaces and symbols but you'd never remember it．
   However，because length matters very much，the surprising truth is that a longish string of random English words，all in lower case-say， "awoken wheels angling ostrich"-is actually much more secure than a shorter password that follows your bank's annoying rules，such as "M nch3st3 r"．

（1）According to the writer，what's the reason for most people to write down their password？

Because it's hard for them to remember so many numbers.

Because it's hard for them to remember so many numbers.

（2）What else do people have to remember if they get locked out of their bank account？

The answers to various security questions．

The answers to various security questions．

（3）According to the Yahoo security breach， "ninja" is among those terrible passwords，isn't it？

Yes，it is．

Yes，it is．

（4）How long does it usually take a hacker to crack a password，such as "fpqzy"？

It usually takes them three and three quarters hours to crack．

It usually takes them three and three quarters hours to crack．

（5）Which password is probably a secure one， " m@nch3st3 r"or " welcome123"？

Neither of them．

Neither of them．

（6）What does a safer secure password possibly consist of？

It consists of completely random letters，numbers，spaces and symbols．

It consists of completely random letters，numbers，spaces and symbols．