---Hi,Nancy.I didn’t know you had come back.So have you graduated from college?---Yes.I _______ French for 5 years in Nanjing.
Edward, you play so well. But I ______ you played the piano.
She brought with her three friends, none of ______ I had ever met before.
I tried phoning her office, but I couldn't ______ .
His sister left home in 1998, and ______ since.
What do you mean, there are only ten tickets? There ______ be twelve.