用中线法进行洞内测量的隧道，曲线部分不应小于( )m。
A．40．B．50．C．60．D．80
参考答案：A
How do you __________ on the radio?[ ]
A. turn
B. turns
C. to turn
According to the passage, only literate people could vote.
A．True
B．False
