There was a loud knock at the door at midnight.The knock woke me up.Who was it?
It couidn"t be my father or mother,because they were staying at home.It couid"t
be a thief.The thief was afraid,and he couidn"t knock at door.It may be my neighbor.Maybe he wanted some help.Oh,it must be my aunt.She likes knocking at theght
door as midnight.