你好,下面例句中的黑体字部分都属于第三人称复数。例句 1:They are all good students. (他们是好学生。)改为否定句: They aren't ( = are not ) good students.例句 2:They like playing football. (他们喜欢踢足球。)改为否定句: They don't like playing football.例句 3:My parents are teachers. (我父母都是老师。)改为否定句: My parents aren't teachers.例句 4:Tom and Jack are good friends. (汤姆和杰克是好朋友。)改为否定句: Tome and Jack aren't good friends.例句 5:People there are warm-heartedand straightforward.( 那里的人们人热情、直率。)改为否定句: People there aren't warm-heartedand straightforward.