Bob has gone to California,I hear.Oh,I wonder when he ------- A leaves B left C was leaving D has left

问题描述:

Bob has gone to California,I hear.Oh,I wonder when he ------- A leaves B left C was leaving D has left

B 我想知道他什么时候走的(已经去加州了,说明“走”这个动作已经是过去了)