15. It is difficult for us to learn a lesson in life ____we’ve actually had that lesson.

A. until　　　　　 　　 B. after　　　　　 　　 C. since　　　　　 　　 D. when

14. The report about the ______ surprised all the ______.

　 A. present situation; people present　　　　　　　　 B. present situation; present people

　 C. situation present; people who present　　　　　 D. situation present; presented people

13. The man kept silent in the room unless _______.

　 A. spoken　 　　　　　　 B. speaking　　 　　　　　　 C. to speak　　 　　　　　　 D. spoken to

12. ______ writing the article, Mrs. Curie even forgot her dinner.

　 A. Absorbed in　 　　 B. Absorbing at　 　　　　 C. Having absorbed by　 D. To absorb in

11. The man is being questioned in relation to the ______ murder last night.

A. advised 　　　　　　　 B. attended 　　　　　　　　　 C. attempted 　　　　　　　 D. admitted

10. -----Can you tell us what is important to a businessman?

　 -----________ information.

　 A. Collect　 　　　　　　 B. Collected　　　 　　　　 C. Having collected　 　　 D. Collecting

9．The professor referred to 　　　　yesterday.

　 A. come　　　　　 　 B. came　　　　　 　　 C. coming　　　　　 　 D. comes