"You have found your lost umbrella,haven't you?" "Yes,I found it behind the door this morning."

问题描述:

"You have found your lost umbrella,haven't you?" "Yes,I found it behind the door this morning."
为什么答语中"found"不用"have found"?

答语中的this morning是过去的时间,故用一般过去时,而不用现在完成时.