国际单位制中压力的基本单位是（）A．kgf/cm2 B．Pa C．bar D．atm_爱下问搜题

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问题单项选择题

国际单位制中压力的基本单位是（）

A．kgf/cm²

B．Pa

C．bar

D．atm

答案

参考答案：B

填空题

用方框中单词的正确形式填空。

meet, get , follow, land, jump

1. I _____ a letter from Tom yesterday.
2. Don't _____ down from the tree. It's dangerous.
3. A UFO _____ on Center Street while I was shopping.
4. I _____ an old friend of mine when I was in Shanghai.
5. Would you like_____ me to do some shopping?

单项选择题

允许多个程序同时进入内存并运行的是

A．程序并发执行

B．多道程序设计

C．程序的顺序执行

D．时间片轮转