The best way to prevent the air polluting _____ , but the sky is still not clear.
Take the note as a reminder_________ you forget to buy some sweets for the kids while shopping there.
The 13:30 train to Shanghai has been put off __________ the heavy storm.
You cannot take back your words _________ they are out of your mouth.
—What’s that noise? —There’s a truck stopping outside. It’s someone _____ something.
Remember me to your parents when you _____ them.