下列句子用be动词的适当形式填空
1.I () a student.You ()a teacher.
2.She () my friend.
3.() you Li Fen?No,I () not.
4.() Mr.green very busy?Yes,he ().
5.He must () at home.
6.The book () very interesting.
7.() cleaners very busy?
8.You and I () good friends.
9.His friends () very funny.
10.The twins () very happy because they are going to the cinema.