We can see light in his office. He___________ be in his office.
As nobody here knows what is wrong with the machine, we ________send for an engineer to handle the problem.
The Spring Festival, a traditional Chinese festival, is celebrated in________Asian countries.
Can you think of some cases ______-people are likely to tell lies?
—Shall we go out for a walk? —Sorry. I’m too busy to ______-for the moment.
The 2008 Olympic Games,_______in Beijing, impressed the world deeply.