根据下列各图填空完成对话。
(1)A:What are you doing, Sam?
B:I am _________.
(2)A:_____ is she?
B:She is Mary.
A:_____ is she doing?
B:She’s writing.
(3)A:_____ _____ your sister?
B:Yes, she is.
A:What ______ _____ _____?
B:She is working.
(4)A:Do you like English?
B:No, I ______.
A:What do you like best?
B:I like ______ best.
(5)A:_____ ______ _______ _______?
B:I’m from England.
A:_____ ______ like singing?
B:Yes, I do.