Not only ______ the book, but he remembered what he had read.

A．he had read

B．had he read

C．did he read

D．was he reading

DS6-11计算机联锁系统，在双机非同步状态下人工切换联锁机，切换后系统处于（）状态。

A.区段锁闭

B.进路锁闭

C.全站锁闭

D.全站解锁