两条电热丝的电阻之比是3：4，通过它们的电流之比是4：3，在相等时间内，它们消耗

产生于黄河流域古老而神秘的文字是 [ ]

A、埃及象形文字

B、苏美尔人楔形文字

C、腓尼基文字

D、甲骨文

下列各句，属于误用否定的是（）。

A．一个人即使办事认真，也不可能不犯错误

B．浙江杭州是无地不美，到处皆景

C．研究美学不能不懂点艺术，否则就摸不着美学的门

D．只有态度坚决，措施严密，才能防止这次财务大检查

阅读理解。

     By creating a distinctive username-and reusing it on multiple websites-you may be giving online marketers

and scammers a simple way to track you. Four researchers from the French National Institute of Computer

Science ( INRIA) studied over 10 million usernames-collected from public Google profiles, eBay accounts,

and several other sources. They found that about half of the usernames used on one site could be linked to

another online profile, potentially allowing marketers and scammers to build a more complex picture of the

users.

     "These results show that some users can be profiled (勾勒轮廓) just from their usernames," says Claude

Castelluccia, research director of the security and privacy research group at INRIA, and one of the authors

of a paper on the work. "More specifically, a profiler could use usernames to identify all the profiles that belong

to the same user, and then use all the information contained in these sites to profile the victim."

     Those who have more unique usernames are more likely to be attacked. The INRIA researchers have

created a tool that can check how unique a username is, and thus how easily an attacker could use it to build

a profile of a person.

     Researchers are exploring ways that the traces of data that people leave on different websites could be

combined and used to track them. A 2010 paper showed that the online groups to which people belonged

could be used to infer their real identity in 42 percent of cases.

     Building profiles of consumers using online information has already become a major industry for marketers

as well as online criminals.

1. What, would be the best title for the passage?

A. Look out for online criminals

B. Your username may betray you

C. Don't ]eave your traces online

D. A unique username is more attractive

2. Online marketers may use your username to ____.

A. get a picture of yours

B. steal from your online account

C. get useful information about you

D. find out your interest or hobbies

3. The main purpose of the passage is probably to ____.

A. warn us of the possible dangers of a unique username

B. tell us how to manage our online information

C. advise us on how to choose a proper username

D. tell us the importance of a username

4. We can infer from the passage that ____.

A. it's hard to build a profile of a person from a username online

B. it's better to use a more complex username online

C. a username online has little to do with the real person

D. we'd better not use the same username on different sites

5. The underlined word "scammers" in Paragraph l most probably means ____.

A. friends

B. criminals

C. victims

D. salesmen

地基中，地下水位的变化会导致地基中土的自重应力（）。

A.增加

B.减小

C.不变

D.可能增大，也可能减小

SCI数据库中通过浏览单篇文献题录可以获得以下信息：（）

A.参考文献（References）查看本篇文献的引文

B.被引频次（TimesCiteD.查看本篇文献被引用的次数，以及引用本篇文献的文献记录

C.相关文献（Related Records）有一篇或一篇以上共同引文的文献称为相关记录

D.可查看所有与此篇文献有共同引文的文献