Could you tell me ?- Certainly. In half an hour.A. when will the train to Beijing l

问题补充：

--- Could you tell me ?

--- Certainly. In half an hour.

A. when will the train to Beijing leave

B. when the train to Beijing would leave

C. when the train to Beijing left

D. when the train to Beijing will leave

答案：

A. when will the train to Beijing leave

B. when the train to Beijing would leave

C. when the train to Beijing left

(答案→)D. when the train to Beijing will leave

解析：句意：你能告诉我去北京的火车什么时候离开吗？当然。半小时后。本句是一个宾语从句，应该用陈述句语序，根据in half an hour可知，应用将来时。故选D。