13. These _________ students show great _________ for learning a new language.

　　14. Politically these nations tend to be _________, with very high birth rates but poor education and very low levels of _________.

　　15. The London Marathon is a difficult race. _________, thousands of runners _________ every year.

　　16. Being _________ of the law is not accepted as an _________ for breaking the law.

　　17. Within two days, the army _________ more than two hundred rockets and missiles at military _________ in the coastal city.

　　18. It is said in some parts of the world, goats, rather than cows, serve as a _________ _________ of milk.

　　19. In view of recent developments we do not think your _________ is practical.

　　20. Jessica was _________ from the warehouse to the accounting office, which was considered a _________.

　　21. It’s not _________ to _________ the experiment without the instruction from our teacher.

　　22. During our growth we have to _________ _________ pains and disappointments.

　　23. You can hire a bicycle in many places. Usually you‘ll have to pay a _________.

　　24. The food was bad and the bill was _________ in this restaurant.

　　25. Dr. Smith was always _________ about the poor and the sick, often providing them with free _________.

　　26. Thomas Jefferson and John Adams died on July 4, 1826, the fiftieth _________ of American Independence.

　　27. Nowadays computers often _________ the task of experiment and _________ in some scientific _________.

　　28. The _________ at the military academy is so _________ that students can hardly bear it.

　　29. The test results are beyond _________; they have been repeated in labs all over the world.

　　30. In order to make things _________ for the people, the department is planning to set up some _________ shops in the residential area.

　　Unit Three

　　1. The _________ are very good at sensing a mood and then _________ it.

　　2. The board of the company has decided to _________ its _________ to include all aspects of the clothing business.

　　3. Doctors warned against chewing tobacco as a _________ for smoking.