液压传动是以液体作为（）来传递动力和动作信号的系统。
A.工作介质
B.执行元件
C.原动力
D.控制元件
参考答案：A
“Have great changes taken place in your village?” “Yes, A new school was ______ in the village last year.”
A．held up
B．set up
C．sent up
D．brought up
开餐时，客人突然感到不舒适或有病怎么办？
