--- Look! It ____ be Jack on the playground.---It ____ be him. Because I saw him enter the school library just now.A. may; mustn’t B. must; can’t C. can; can’t
-How many ____________did you do yesterday? -Six Patients were ____________on.
Nothing will prevent us_________our dreams.
-Are you going to Shanghai for vocation? -Yes.We want you to_______us with some information about it.
All of us find_______necessary to take exercise every day.
My parents warn me __________too many computer games.