His grandpa was so poor at that time that he had to get up at           dawn every day and walk to the factory in            distance.

A．×; a

B．×; the

C．a; the

D．the; the

关于循环氢压缩机启动时必须具备的信号条件，下列说法正确的是（）。

A.高压蒸汽温度大于规定值

B.密封油温度规定值

C.调速油／润滑油温度规定值

D.润滑油高位槽液位大于规定值