二、单项选择(每题1分,共15分)
( )21. —What can I do for you?
—I want _______ iPad for my son. He needs _______.
A. an; one B. a; one C. an; it D. a; it
( )22. —Are these books ________?
—No, they are not mine. They belong to _______ .
A. your; her B. yours; her C. you; hers D. yours; she
( )23. —They Shanghai two days ago.
—Yes. They for two days.
A. leave for; were away B. left for; have been left
C. leave for; have been away D. left for; have been away