He bought a book yesterday.
He taught English last year happily
He saw a man in the classroom.
改为否定句. ps:不是否定回答.
He bought a book yesterday.
He taught English last year happily
He saw a man in the classroom.
改为否定句. ps:不是否定回答.
He didn't buy a book yesterday
He didn't t each English last year happily
He didn't see a man in the classroom.
He didn't buy a book yesterday.
He didn't teach English last year happily
He didn't see a man in the classroom