关于压强的概念，下列哪种说法是正确的（） A．压强只和压_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题选择题

关于压强的概念，下列哪种说法是正确的（　　）

A．压强只和压力有关

B．压强只和受力面积有关

C．压强和压力及受力面积都有关

D．压强和压力及受力面积都无关

答案

答案：C

选择题

We arrived home at 9:00 in the evening, ________most people had already had supper.[ ]

A. at that time

B. by that time

C. at which time

D. by which time

单项选择题

ICMP协议属于TCP/IP刚络中的______协议，ICMP报文封装在______包中传送。

A．IP

B．TCP

C．UDP

D．PPP