—Look at the girl! Is it Susan?    —No, it __________ be her. She has gone back to her hometown. 

—You __________ in the south of China, didn’t you?—Yes, but now I like living here though it’s cold all the year around. 

I was late for school because my alarm didn’t_________.

Helen has no friends _______.

 —Will someone go and get Dr White?   —He’s already been _________.