—Who______ it be that is knocking at the door? —It ______ be Father, but I’m not sure.
You _____ the exam, but you were too careless.
-Are you free tomorrow evening?-Sorry, I’m afraid I ______a friend off then.
_____he said in the lecture has a great effect on me.
The teacher warned her students ______late for the sports meet next Monday.
The soil is becoming poor because farmers here mostly use only one kind of chemical fertilizer for several years________.