作为纠错码的例子，考虑只有4个有效码字的代码0000000000，000001111

支付密码器账户密钥更改，从密钥更换日起，用原密钥签发的（）在其有效期内核验。

A.全部凭证

B.支票

C.结算业务申请书

D.经中国人民银行批准的其他支付凭证

(4分)化学就在我们身边，它与我们的生活息息相关。请从

A．纯碱

B．熟石灰

C．天然气

D．硝酸钾这四种物质中，选择适当的字母序号填在相应位置。（1）我国实施的“西气东输”工程输送的物质            

（2）用于生产玻璃、造纸、纺织和日用化学工业的物质            

（3）农田施用的复合肥               

（4）能用于改良酸性土壤并可用于配制农药波尔多液的物质                 

一批零件中有10个合格品，2个次品，安装机器时从这批零件中任选1个，取到合格品才能安装；若取出的是次品，则不再放回，

(1)求最多取2次零件就能安装的概率；

(2)求在取得合格品前已取出的次品数ξ的分布列．

患儿，出生5天。全身冰冷，僵卧少动，反应极差，气息微弱，哭声低怯，吸吮困难，面色苍白，肌肤板硬而肿，范围，50%，皮肤暗红，尿少。唇舌色淡，指纹淡红不显。用复温方法治疗，要求达到正常体温的时间为

A．2小时

B．4～6小时

C．8～10小时

D．12～24小时

E．24～48小时

Americans usually consider themselves a friendly people. Their friendships, however, tend to be shorter and more casual than friendships among people from other cultures. It is not uncommon for Americans to have only one close friend during their life-time, and consider other "friends" to be just social acquaintances. This attitude probably has something to do with American mobility and the fact that Americans do not like to be dependent on other people. They tend to "compartmentalize" friendships, having "friends at work" ,"friends on the softball team", "family friends", etc.

Because the United States is a highly active society, full of movement and change, people always seem to be on the go. In this highly charged atmosphere, Americans can sometimes seem brusque or impatient. They want to get to know you as quickly as possible and then move on to something else. Sometimes, early on, they will ask you questions that you may feel are very personal. No insult is intended; the questions usually grow out of their genuine interest or curiosity, and their impatience to get to the heart of the matter. And the same goes for you. If you do not understand certain American behavior or you want to know more about them, do not hesitate to ask them questions about themselves. Americans are usually eager to explain all about their country or anything "American" in which you may be interested. So much so in fact that you may become tired of listening. It doesn’t matter, because Americans tend to be uncomfortable with silence during a conversation. They would rather talk about the weather or the latest sports scores, for example, than deal with silence.

On the other hand, don’t expect Americans to be knowledgeable about international geography or world affairs, unless those subjects directly involve the United States. Because the United States is not surrounded by many other nations, some Americans tend to ignore the rest of the world.

The general topic of the passage is（）

A. American culture

B. American society

C. Americans’ activities

D. Americans’ personality