Why didn't you give the wallet to the man at once He---(disappear)before I realized it was his.

Why didn't you give the wallet to the man at once He---(disappear)before I realized it was his.
Why didn't you give the wallet to the man at once He---(disappear)before I realized it was his.

Why didn't you give the wallet to the man at once He---(disappear)before I realized it was his.
过去完成时：had disappeared
因为实在realized之前发生的

had disappeared

has disappeared

你为什么不马上把钱包还给他？
在我意识到钱包是他的之前那人已经消失了。