She heard him the piano when she walked past his room.
_______useful the information he gave us is !
-----Do you know _____ this teddy bear belongs to? -----Let me see. Oh, it’s _____.
Where is my ________other sock? I can’t find it.
Excuse me. Could you tell me ______?
—Mr. Wang, please _____ how to get there and the cost of the trip.—All right. I’ll make it at once.