We stayed there and watched the opera ______ an hour.

As a top student in our class, it’s good _________ Jim to help us when we’re in need.—Yes. It is also good ___________ him to exercise for an hour every day.

Listen! I hear some birds ___________ thetree.

I want to buy a blue jacket to ________my blue trousers

You won the first prize in the Physics competition.— _________. I made several terrible mistakes.