______ do you know about table manners in Korea?

— ______ his bike is lost? — He has to go to school on foot. 

---Hi. Lucy! What’s wrong with you? You look so worried.---I have many problems to solve, but I don’t know ___________ first. 

______ is important for us ______ learn computer.

---- _____ do you play football? ----  Once a week.