—Why are those people gathering in the middle of the street?—I don’t know. There ________ be an accident.

—God！My cell phone is missing.—You ________ have left it at home.I heard you telephone our daughter in the bathroom.

He ________be at home because the light in his room is on.

—Must I return the book to you now, Jack? —No, you _____. You can give me back tomorrow.

The teacher propose that Jack   ___ maths or physics instead of English because he was quick at numbers.