Someone is knocking at the door. Go and see_________.

A. who is it        B. who it is      C. who is he            D. who he is

—Someone is knocking at the door, dad!

—Go and see ________.

A. who is it　　 B. who it is　　　 C. who was it　　　 D. who it was

—Someone is knocking at the door, dad!

   —Go and see ________.

A. who is it            B. who it is           C. who was it            D. who it was

 There is someone ___________ at the door. Go and see who it is.

A: knock          B: knocked        C: knocking    D: to knock

A. knock; it

B. knocking; it

C. knocking; he

D. knock; be