As the world’s population continues to grow,the ________ of food becomes more and more of a concern.
—I want to go to the library but I am afraid I am not in the right _____. — _____. Go ahead.
—Would you rather come on Friday or Saturday? — _____.
—Did you look up the time of trains to Shanghai? —Yes, the earliest train is _____ to leave at 5:30 am.
--Did Mary come to your birthday party?--No. I __________ her, but she was away on business.
All the preparations_______, we're ready to start.