（）当连续陡坡由几个不同坡度值的坡段组合而成时，应对纵坡长度_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题多项选择题

（）当连续陡坡由几个不同坡度值的坡段组合而成时，应对纵坡长度受限制的路段采用平均坡度进行验算。

A.高速公路

B.一级公路

C.二级公路

D.四级公路

答案

参考答案：A, B

单项选择题

报文摘要用于______。

A．报文鉴别

B．报文加密

C．报文解密

D．邮件传送

选择题

—I called you at six o'clock yesterday evening but there was no reply.

—Oh, I'm sorry. I _______ dinner at my friend's. [ ]

A. was having

B. is having

C. had

D. have