What ______ you ______ when the telephone rang just now?
China has a history of more than five ________ years.
The girl ________ by the lake yesterday.
– I hear Yang Yan made an English speech at the graduation ceremony yesterday.- ______, and _______.
I don’t know if he tomorrow. If he , I’ll tell him about it.
We can’t work out the physics problem. Can you tell us ____?