It ________ be the postman at the door.It's only six o'clock.( 2011·江西)
---Were you satisfied with the exam result? ---Not a ______. I should have done much ______.
It's no such ____ long distance from here to ____ supermarket. We can walk there.
The quality of the teachers will influence the students,and ________, the quality of the students will influence the teachers.
That was the last time I saw my father before he _____.
The experiment __to be .