_____ in the strange city, poor Bill fell to _____.
19.There are two buildings, ____ stands nearly a hundred feet high.
18.When we were young, every evening we ____ stay at home waiting for our mother.
17. — I’m sorry. I ____ hurt you. — Forget it.
16. —Who____ it be that is knocking at the door? —It ____ be Father, but I’m not sure.
15. —Why is Mr. Li so happy this morning? —Because he was honored with a(n) ____ for excellence in teaching.