All those second-hand goods are sold at before.
The number of smokers in the countryside is usually greater than _______ in cities.
Most of us see a doctor ______ when we get a cold or something.This won't cost us a lot.
May I use your bike? I'm going to see my uncle who _______ this city.
It is playing computer games _______ the boy spends most of his spare time.
---What's he size of the smaller one? ---It's _______.