18. Dr. Frank failed many times but he finally ______ to find a successful way to solve the problem.

17.-Who told you my email address?

　 -I don’t remember clearly. It _______ Karen.

　 -It _______ Karen. She doesn’t know my email address.

16. Since I won the big prize, my telephone hasn’t stopped ringing. People __________ to ask how I am going to spend the money.

15. Some of you have finished Book One.________, you can go on with Book Two.

14. The female scientist Ostrom devoted herself _______ to her research and it earned her the Nobel Prize for Economics in 2009.

13. - Where will you start your work after graduation?

　 　- Mum, it’s not been decided yet. I __________ continue my study for a higher degree.

12. - I’m sorry, I shouldn’t have been so rude to you.

　 - You________ your temper but that’s OK.

11. The news spread quickly all over the world ______ Michael Jackson died a sudden death.

10. Take care during the holidays! Drinking too much can ______ heart disease and cause high blood pressure．

9. According to a recent research, many teenagers have no dreams ______ to lead a comfortable life.