---What on earth are the police busy with? ---They have been looking into how the plane crash _______.
Tom as well as two of his classmates _____invited to the party.
The old ____well looked after by the government in China.
______the room, a letter was seen lying on the desk.
When I got home I got a message pinned on the door, ______, “Sorry to miss you. Will call later”
We shouldn’t complain about being poor; many families are even ______.