用may， might， probably， possible，can’t填空。
【小题1】— Listen! Helen is singing in the next room.
— It          be Helen. She has gone to Beijing.
【小题2】He told me that he             be late for school.
【小题3】It’s            for us to finish the task before 7 o’clock.
【小题4】It            rain later. So take an umbrella with you.
【小题5】It will             snow tomorrow， so I will stay at home and read a book.