元组的每个分量必须是不可分的数据项这叫做______。

阅读理解.

     Many students in the USA always take the school bus to school every day. Parents think taking the

school bus is very safe(安全的). But sometimes it is also dangerous. Some students died(死亡) because

they broke the school bus rules. Here are some school bus rules:

     ◆Amve at the bus station early. 

     ◆Wait for the bus at the bus station. 

     ◆Don't play around the bus. 

     ◆Don't run everywhere at the bus station. 

     ◆Don't walk or fight in the bus when it is going. 

     ◆Don't try to leave the bus until it stops. 

     These rules are good for students. Remember them and don't break them. So you can keep yourself

safe.

根据短文内容,判断下列句子正( T)误( F) 。

( )1. Taking the school bus to school is always safe.

( )2. Students can run everywhere at the bus station.

( )3. Students have to sit on their seats when the bus is going.

( )4. Students can't get to the bus station late.

( )5. It can be dangerous if students break the school bus rules.

在OSI参考模型中，属于传输层的协议是（）。

A.TELNET

B.SNMP

C.TCP

D.ICMP

医师处方写续随子时，应付（）

A.马钱子

B.青葙子

C.地肤子

D.木鳖子

E.千金子

拔伸牵引的作用不包括（）。

A.矫正缩短移位

B.调动肌肉夹板作用矫正移位

C.促进血液循环

D.为施行其他手法创造条件

E.暂时固定骨折