作业帮He is putting up some signs asking for old booksHe is putting up some signs asking for old books and magazine.为什么要用ask的ing形式
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/27 07:35:07
He is putting up some signs asking for old books
He is putting up some signs asking for old books and magazine.为什么要用ask的ing形式
因为前面有is,所以后面所有的动词都用ing形式