下列物质能用烧碱作干燥剂的是（ ） A．H2 B．HCl C．CO2 D．SO2

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       In 1901, the citizens of Colorado Springs in the USA decided to collect everyday items and to

seal (封住)them in a special box. The box was marked "To be opened after midnight, December 31st,

AD 2000",and was kept in the Colorado College Library.

       One hundred years later, on the appointed (约定)day, 300 people gathered to watch the opening

of the box. Many in the crowd were the descendants (后代)of people who had placed things inside the

box.

       When the box was opened after midnight, the things inside the box were in very good condition.

There were newspapers, photos, diaries, name cards, family trees, books and lots of letters, including

one written by Theodore Roosevelt,  who became the President of the USA later that year.  One of

Roosevelt's friends lived in Colorado Springs at that time.

       Many of the letters were written to their descendants. They describe the hopes that the people of

1901 had for the people of the next century. At that time, Colorado Springs had just a few thousand

people. Now nearly half a million people live there.

       Colorado College Library has scanned the materials and put them on a website. Cecil Muller,

whose grandfather had placed a collection of postcards in the box, said that the time capsule was a

great treasure. "This is a wonderful educational resource(资源).  We can learn so much about our

history,"he said. "I never knew my grandfather, but now I feel very close to him. "

1. According to the passage, "time capsule" means ______.

A. a collection of clocks and watches

B. a machine for travelling through time

C. a collection of items for people to look at in the future

D. a collection of unwanted items

2. Many of the letters in the time capsule talked about.

A. the history of the town

B. the people who lived in the town  

C. the politics of the USA    

D. people's hopes for the future

3. Cecil Muller says that the time capsule ______.

A.helps him to get to know his grandfather

B. is worth a lot of money

C. brings back his memories of his grandfather

D. helps him to remember his younger day

分组交换网络有数据报和虚电路两种方式，下列描述错误的是（）。

A.虚电路的路由选择仅发生在虚电路建立时，而数据报方式每个分组都必须独立寻找路由

B.在通信过程中网络设备故障会导致已建立好的虚电路断开，必须重新建立连接

C.数据报方式一般不保证分组的接收顺序与发送顺序一致

D.虚电路方式的分组交换控制复杂，所以一般来说分组头部开销比数据报方式大

简述心肺复苏徒手操作法的目的？

行政诉讼中人民法院判决重新作出具体行政行为是对下列哪类判决的一种补充（）

A.判决变更

B.判决限期履行法定职责

C.判决撤消

D.判决维持

E.判决作为

银量法测定苯巴比妥含量时，所用溶剂系统为（）

A.3%碳酸钠溶液

B.甲醇

C.乙醇

D.丙酮

E.甲醇及3%无水碳酸钠溶液