问题补充:
--- I hear Sam has gone to Qingdao for his holiday.
--- Oh, how nice! Do you know when he ?
A. left
B. was leaving
C. has left
D. had left
答案:
(答案→)A. left
B. was leaving
C. has left
D. had left
解析:句意:我听说萨姆已经去了青岛度假。——哦,太好了!你知道他什么时候离开的吗?结合语境可知宾语从句中描述的是过去某时发生的动作,故用一般过去时态,选A。