电子防滑器的排风阀一般安装在制动支管与（）之间。
A.工作风缸
B.副风缸
C.制动缸
D.缓解风缸
参考答案：C
"What are you doing for vacation?" "I'm going _____ with my friends." [ ]
A. camp
B. camps
C. camping
D. to camp
校外活动是课堂教学的延续。( )
