Could you please me tell me ________?
---How long has Mr. White __________ Joan?---I’m not sure. Maybe they __________ five years ago.
----How about the pollution in the countryside?--- Luckily, it's not as serious as _______ in the big cities.
---Someone is knocking at the door. Who may it be?---It ______ be Tom. He is still in the school.
Lucy had few close friends. So she didn’t know ________ about the trouble.
Her singing lessons her five hours a week.