gh the causes of cancer ____, we do not yet have any practicalway to prevent it

John, you are asked to give a presentation of our product at tomorrow’s conference.—________. I am not good at public speech, you know.

can’t ____my addiction to computer games.—Come on! Computer games are ____. We play games on the iphone now. [ ]

It’s not what you do once in ____ while butwhat you do day in and day out that makes ____ difference

he factors already referred to,people sometimes feel insecure because their motives are misunderstood byothers