JSBXC—850型继电器通过不同的接线，可获得180s、30s、13s、3s等4种延时。
参考答案：对
Maxrnize命令用于______。
— ____________________
— A board, a light and desks. [ ]
A. What's in your classroom?
B. What's in your bag?
C. How many books?
