股骨颈骨折中易发生头坏死的类型为（） A.基底型 B.头下型 C.经颈型 D.不完全

阅读理解。

     Most American families are smaller than the families in other countries. Most American families have one or two

parents and one or two children each.

     When children are young, parents often ask them to  do  some work around the house.   And   in  many families,

parents often give the money for doing the housework by children. And children can learn how to make money for

their own use. Some children will find a part-time job(兼职) to get the money to use. So children know how to make

money and take care of themselves when they are young.

     Children in the USA will   leave their parents' home  when they grow up.   They usually live far from their parents

because they want to find good jobs. They often write to their parents or telephone them. And they often go to visit

their parents on holidays.

     Parents usually let their children choose their own jobs. Americans think it important for young people to decide

on their lives by themselves.

1. Most of American families have ______________ people each.

A. one or two

B. two or four

C. tow to four

D. about five

2. Children have to do some _______________ at home when they are young.

A. housework

B. homework

C. shopping

D. office work

3. They can get money for their ______________ when they are young.

A. housework

B. part-time jobs

C. voluntary (志愿的) work

D. both A and B

4. Do children in America usually live with their parents when they grow up?

A. Yes, they do.

B. No they don't.

C. We can't find the answers.

D. Some do, some don't.

5. Children ____________their parents.

A. write to their parents or telephone.

B. write to their parents and visit

C. write to their parents, telephone them or visit

D. go to their parents' home and meet

在DMA方式下，CPU与总线的关系是()。

A．只能控制数据总线

B．只能控制地址总线

C．成隔离状态

D．成短接状态

在钱学森心里，国为重，家为轻，科学最重，名利最轻。五年归国路，十年两弹成。开创祖国航天事业，他是先行人，披荆斩棘，把智慧锻造成阶梯，留给后来的攀登者。这表明[     ]

①他情系祖国，是一位坚定的爱国者

②他有以祖国和人民利益为重的崇高理想

③要为祖国作贡献，就不能实现个人利益

④他有求真求是、开拓创新的科学精神

A．①②③

B．①②④

C．①③④

D．②③④

何时禁止使用防雨剂系统？（）

A.双发关车时

B.在地面速度低于80KT时

C.高度层大于FL150

归档文件材料主要来源是（）。

A、本企业工作活动形成的文件

B、上级单位的来文

C、下级单位上报的文件

D、有关机关和不相隶属单位发来的文件