It is useful to be able to predict the extent _____ a price change will affect supply and demand.
Every year, many competitors from famous university come to the Thames to compete each other boating.
We can never expect bluer sky unless we create less polluted world.
The coat you wear now is the same ________ I bought yesterday.
The rest of the money __________ to him.
— Hurry up, the train ________ at 8 O’clock. — I________, Mum.