We have just heard a warning on the radio ________ an earthquake is likely to strike that area again.
He is giving her French lessons in __________ for her teaching him English.
-Shall I __________ addresses with you ?-OK. Hongxing Road, No 53. Yours?
He's teaching me French __________ my teaching him Chinese.
We have to give the users something new __________ what we've already offered, which is the only way to broaden the appeal of the website.
-What can I do for you?-I'd like to __________ this blue shirt for a bigger size.