问题补充：
— I saw Dave in the lift this morning.
— Really? He around here for a long time.
A. won’t be seen
B. wasn’t seen
C. hadn’t been seen
D. hasn’t been seen
答案：
A. won’t be seen
B. wasn’t seen
(答案→)C. hadn’t been seen
D. hasn’t been seen
解析：答句中Dave没有被看到没有持续到双方正在对话的现在，而是今天上午，所以用过去完成时态
