题目内容：

My father has been an engineer for twenty years.(保持句意不变)
My father has ___ ___ an engineer for twenty years.
这题的空格中该怎么填?

优质解答

My father has worked as an engineer for twenty years.
我爸爸当工程师已经20年了.
as…作为…
O(∩_∩)O~~