30．—Peter looked tired and a little absent-minded at the meeting． —He _____ up too late．

Christmas is a holiday usually celebrated on December 25th _____ the birth of Jesus Christ[ ]

Your son has kept _________ fortwo hours. You’d better ask him to have a rest.

rl had hardly rung the bell thedoor was opened suddenly, and her friend rushed out to greet her

He had some trouble, but he kept on_______________ and didn’t give up.