伸直型桡骨下端骨折的移位特点是（）。 A.近折端向背侧移位 B.骨折断端向背侧成角

根据短文内容，选择正确答案。

     My friend Bob has an interesting hobby. He likes collecting stamps. He spends a lot of time on his

stamp collection after school hours. Now he has hundreds of stamps from all over the world.

     Bob likes stamps with pictures of animals and plants on them. In this way, he learns the names of

many animals and plants. He also borrows books on animals and plants from his school library. He learns

a lot from them.

     Sometimes Bob has many stamps of the same kind. He gives some of them to his friends. And they

give him others in return (回报).

     Bob often writes to his friends in many countries. He sends them stamps of his country. In return, they

send him stamps of their countries. 

     Bob thinks collecting stamps can bring him much knowledge, pleasure and happiness. And he can

make more friends from all over the world.

1. Bob spend a lot of time on his hobby ______.

A. during his holiday

B. after school hours

C. during school hours

D. on Sundays

2. Bob learns a lot about animals and plants from ______.

A. his teachers

B. his friends

C. his stamps      

D. his classmates

3. When Bob has stamps of the same kind, he ______.

A. sells them to his friends

B. throws then away

C. keeps them for himself

D. sends some of them to his friends

4. Bob often sends some stamps to his friends in many countries, and the friends ______.

A. send him other stamps in return

B. write him letters for thanks

C. give him some money

D. send him some foreign coins

5. Collecting stamps can make Bob ______.

A. very happy

B. learn much knowledge

C. make more friends

D. A, B and C

需要他人帮助转移，转移相关主要关键肌的肌力为（）

A.≥2级

B.≤2级

C.≥3级

D.≤3级

E.>3级

读图3和图4，回答下列问题。（14分）

图3　1950－2000年中国人口自然变动　　图4　中国人口增长变化状况的预测

（1）20世纪60、70年代我国人口增长模式属于         （2分）

（2）我国人口总数达到最高峰的时间大约在          年,2010年后我国人口死亡率缓慢上升的主要原因是          _____  。（4分）

（3）未来20年，我国面临的人口问题主要有哪些？将给我国社会经济和环境造成哪些影响？（8分）

甲公司为其价值500万元的设备向某保险公司投保保额为250万元的保险，在保险责任期限内发生了保险事故，致使该设备严重受损，经估价实际损失达300万元。对此，保险公司应当赔偿甲公司（）万元。

A．150

B．250

C．300

D．500

电动机转子外径不大于200mm时，转子静平衡允差极限（）g。

A.2

B.3

C.4

D.5