英语 (2 19:15:12)He began to do his homework when his mother came back.（同义句）
问题描述：
英语 (2 19:15:12)
He began to do his homework when his mother came back.（同义句）
答
He didn't begin to do his homework untill his mother came back.
He began to do his homework as soon as his mother came back .
答
He began to do his homework as soon as his mother came back .
答
He didn't begin to do his homework untill his mother came back.