----How many birds can you see in the tree?----. All the birds have flown away.A. NoneB. N

问题补充：

----How many birds can you see in the tree?

----. All the birds have flown away.

A. None

B. No one

C. Nothing

D. A few

答案：

(答案→)A. None

B. No one

C. Nothing

D. A few

解析：考查不定代词的用法。根据下句，鸟全飞走了，因此树上一只也没了。a few“几个”；no one“没有一人”；nothing“没有什么”；none“一个也没有”。