—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
–What can I do for you? –I'd like to buy a bicycle for my son, _____ at a proper price but of great use.
The place ____ the bridge is supposed to be built should be _____ the cross-river traffic is the heaviest.
He tried hard to keep calm in face of the policemen, but the sweat on his forehead _____ him _____.
______, this kind of disease can do great harm to people over there.
–People should stop using their cars and start using public transport. –______. The roads are too crowded as it is.