He cut a piece of bread before lunch.(改为否定句) He ()()a piece of bread before lunch.
问题描述：
He cut a piece of bread before lunch.(改为否定句) He ()()a piece of bread before lunch.
答
He didn't cut a piede of bread before lunch.
before lunch在午餐前,所以要用一般过去式.一般遇到有before的,都用一般过去式.