单选题 Passwords are everywhere in computer security. All too often, they are also ineffective. A good password has to be both easy to remember and hard to guess, but in practice people seem to pay attention to the former. Names of wives, husbands and children are popular. "123456" or "12345" are also common choices.
That predictability lets security researchers (and hackers) create dictionaries which list common passwords, useful to those seeking to break in. But although researchers know that passwords are insecure, working out just how insecure has been difficult. Many studies have only small samples to work on.
However, with the co-operation of Yahoo!, Joseph Bonneau of Cambridge University obtained the biggest sample to date—70 million passwords that came with useful data about their owners.
Mr Bonneau found some interesting variations. Older users had better passwords than young ones. People whose preferred language was Korean or German chose the most secure passwords; those who spoke Indonesian the least. Passwords designed to hide sensitive information such as credit-card numbers were only slightly more secure than those protecting less important things, like access to games. "Nag screens" that told users they had chosen a weak password made virtually no difference. And users whose accounts had been hacked in the past did not make more secure choices than those who had never been hacked.
But it is the broader analysis of the sample that is of most interest to security researchers. Despite their differences, the 70 million users were still predictable enough that a generic password dictionary was effective against both the entire sample and any slice of it. Mr Bonneau is blunt: "An attacker who can manage ten guesses per account will compromise around 1% of accounts." And that is a worthwhile outcome for a hacker.
One obvious solution would be for sites to limit the number of guesses that can be made before access is blocked. Yet whereas the biggest sites, such as Google and Microsoft, do take such measures, many do not. The reasons of their not doing so are various. So it"s time for users to consider the alternatives to traditional passwords.

单选题 People tend to use passwords that are ______.

【正确答案】 A

【答案解析】[解析] 细节题。根据第一段第三句“A good password has to be both easy to remember and hard to guess, but in practice people seem to pay attention to the former.”可知，一个好的密码应该兼具容易记忆和难以猜测这两个特点，但在实际生活中，人们似乎更注重前者。换句话说，虽然密码的两个特点都很重要，但人们在使用中还是更注重更容易记忆，因此A选项easy to remember“易于记忆”符合题意，为正确答案。

单选题 Researchers find it difficult to know how unsafe passwords are due to ______.

【正确答案】 D

【答案解析】[解析] 细节题。题干中的unsafe passwords是对文章第二段第二句中passwords are insecure的同义转述，由该句可知，研究者认为想要测算密码不安全的程度是很困难的，因为许多研究都只能在少量的样本上展开工作，这说明困难是由于缺少样本造成的，因此D选项limited size of samples“样本大小受限”符合题意，故D为正确答案。

单选题 It is indicated in the text that ______.

【正确答案】 C

【答案解析】[解析] 推理题。A选项“印尼人对密码安全很敏感”与文章第四段第三句中“those who spoke Indonesian the least”即“那些说印尼语的人的密码最不安全”表达相矛盾，可排除。B选项“年轻人倾向使用安全的密码”与第四段第二句“Older users had better passwords than young ones.”即“年长的人的密码比年轻人的密码更安全。”表达相矛盾，可排除。D选项“信用卡的密码通常是安全的”与第四段第四句“Passwords designed to hide sensitive information such as credit-card numbers were only slightly more secure than those protecting less important things, like access to games.”表达相予盾，亦可排除。C选项“提示窗口对密码安全帮助不大”与第四段第五句“"Nag screens" that told users they had chosen a weak password made virtually no difference”表达一致，故C为正确答案。

单选题 The underlined word "compromise" in Para. 5 most probably means ______.

【正确答案】 C

【答案解析】[解析] 语义题。由第五段第三句中“An attacker who can manage ten guesses per account will compromise around 1% of accounts.”可知，攻击者对一个账户进行10次密码尝试输入就会对约1%的账户造成危害。结合该段最后一句“And that is a worthwhile outcome for a hacker.”可知，“这1%账户对黑客来说，已经是一个很值得的结果了。”这说明他们会根据对密码的猜测来破解账户，因此对账号造成威胁。A选项comprise“包括，构成”；B选项compensate“补偿，赔偿”；C选项endanger“濒临灭绝的”，可引申为“遭受威胁的”；D选项encounter“遭遇，偶然碰见”。对比四个选项，只有C选项endanger最符合题意，故C为正确答案。

单选题 The last paragraph of the text suggests that ______.

【正确答案】 B

【答案解析】[解析] 推理题。根据题干可定位至文章末段。A选项“网络使用者要规范他们的网上行为”，在文中并未提及，可排除；C选项“大型网站限制尝试输入密码的次数”太过绝对，最后一段虽然提到谷歌和微软采取了这样的措施，但并不是所有的大型网站都这样做了，故排除C；D选项“大型网站为用户提供方便的登入”，文中也未提及，亦可排除。B选项“网络使用者要靠自己注意网络安全”与末段末句的“so it"s time for users to consider the alternatives to traditional passwords.”表达一致，故B为正确答案。