We'd better wait     more minutes. I think Jeff will come soon,

He ______ sleep, although he tried to, when he got on such a hunt for an idea until he had caught it.

--______you swim? -- No, I can’t. 

— Who’s singing in the next room?— It ____ be her . She has gone to New York.

It has been announced that students         remain in their seats until all the papers have been collected.