早教吧 育儿知识 作业答案 考试题库 百科 知识分享

He worked on it for five years.对for five years提问

题目详情
He worked on it for five years.对for five years提问
▼优质解答
答案和解析
How long did he work on it
这里是对时间提问,问时间长短的.所以用how long