I hear Sam has gone to Qingdao for his holiday.Oh how nice! Do you know when he ?

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。