The boy was so tired that he fell asleep _____________ his mother could take off his clothes．

A．before

B．after

C．while

D．where

接收来自于（）的故障信息并汇集它自己的故障，然后，把这些故障信息传递给（）

A.GCU、GPCU、CFDIU；

B.GPCU、GCU、CFDIU；

C.EGIU、GCU、GPCU。