题目内容：

I stood dthere until the plane in the sky

优质解答

我一直站在那里,直到飞机起飞.

追问：

I stood dthere until the plane in the sky A has disappeared B disappeared C had disappeared D would disappeared

追答：

选C had disappeared 。我站‘stood’这个动作已经过去，飞机消失‘disappear’还发生在我站之前，过去的过去，要用过去完成时。