请问这道初二英语题为什么用didn't he?

问题描述:

请问这道初二英语题为什么用didn't he?
He must have done his homework last night,didn't he?
为什么不能用 haven't he?

因为后面有一个LAST NIGHT,说明了在说的是昨天晚上的事,所以要用过去式