—Are you coming to Jeff's party?—I'm not sure.I ________ go to the concert instead.

You'd better not ride the bicycle on snowy days; you ______ fall．

—Listen ! Helen is singing in the next room.—It _______ be Helen. She has gone to Beijing.

 Next week, ____ the students will have a basketball game.

—Do you know where Mary is? I couldn’t find her anywhere.—Well . She        have gone far—her coat’s still here.