By the middle of the 21st century, the vast majority of the world's population __________ in cities rather than in the country.
Mum is coming. What present _______ for your birthday?
The bell ____ the end of the period rang and we had to stop our discussion
—Where did you find the professor who made the speech yesterday? —It was in the hall ______ the students often have a meeting..
Sorry to disturb you, ______ could I speak to you for a few minutes?
I wasn’t interested in the film at _____ first, but after ____ time I began to like it.