. Don't go too far into the sea, children, or the waves will _____ you off your feet.
--I'm sorry I made a mistake!-- Nobody is perfect.
The airport ___next year will help promote tourism in this area.
Nowadays people are more concerned about the environment ___ they live.
____ which university to attend, the girl asked her teacher for advice.
He is so busy. He cannot afford enough time with his son ____he wants to.