--- 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
网友回答
(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。