---There’s someone knocking on the door. Who _________ it be?---It must be John. He promised to be here at 8:00.
It was a nice meal, _______ a little expensive.
Bring the plants into a warm room ________ they will grow quickly.
It is reported that it is 100 years ______ Qinghua University was founded.
The boy, as well as his friends, _______ watching TV last night.
______ is known to all, Taiwan is a part of China.