Only when________ possible to settle the problem.
——Could I speak to Mr Brown? —— ______ , I'1l go and see if he is in.
Your English teacher looks very young; He _____ be over 30.
——Need I clean the room now? ——Yes, you _____ , but you ______ ask someone to help you.
——Don't forget to come to my birthday party tomorrow.——______.
What do you think ______ an apple ______ to the ground?