I watched the man for a long time and wanted to know.A. whether I have seen him beforeB. w

问题补充：

I watched the man for a long time and wanted to know.

A. whether I have seen him before

B. where I had seen him before

C. that I had seen him before

D. when did I see him

答案：

(答案→)A. whether I have seen him before

B. where I had seen him before

C. that I had seen him before

D. when did I see him

解析：考查宾语从句。所有的宾语从句都使用陈述语序，排除CD。句意：我观察那个人很长时间。想知道我是否在以前看见过他。根据句意说明A正确。