问题补充：
---Could you please tell me ? ---Of course. For over ten months.
A. how long has he left school
B. how long he has left school
C. when he left school
D. how long he has been away from school
答案：
A. how long has he left school
B. how long he has left school
C. when he left school
(答案→)D. how long he has been away from school
解析：根据题干，我们可知本句是一个宾语从句或间接引语。宾语从句或间接引语的语序应该用陈述句语序，故排除A；根据 For over ten months可知，是提问时间段的，故排除C，根据与For over ten months连用的必须是延续性动词，而left是非延续性动词，故排除B，所以本题选D。
