天车控制电路是由（）电路、大车电路、小车电路和升降电路组成．
参考答案：保护
—Say, Jane, will you come with me to the game Friday?
—______, Bob, but I promised Mary I’d go with her.
A．Forget it
B．Thanks
C．Take it easy
D．My pleasure
请简述DRNC820业务处理子系统的数据处理单元的实现单板，功能模块组成及作用
