将下列句子改成祈使句，并将其改为祈使句的否定形式。
1、They come to the front and point to me.
2、You can sit on this seat.
3、He is listening to music.
4、You are a good man.
5、He is cleaning the classroom.
6、She can wash clothes for her grandma.
7、You should stay at home today.
8、Tom can answer my questions.
9、You would like to read the new words for us.
10、They are sweeping the floor.
11、You did your homework carefully.
12、They can take bus No. 5 to No. 1 Middle School.
13、You should do it again.
