TOEFL Level - Lesson 261. Fire-resistant materials are used to retard ________ of modern aircraft in case of accidents.
2. Because the United States does not have much oil anymore, imported oil ________ used more and more.
3. The FDA was set up in 1940 ________ that maintain standards for the sale of food and drugs.
4. If a ruby is heated it ________ temporarily lose its color.
5. Robots are being used increasingly in industry as they can work on large jobs faster, are more precise and ________.
6. The algebra of sets ________ Boolean algebra.
7. That magnificent ________ temple was constructed by the Chinese.
8. ________ the formation of the Sun, the planets, and other stars began with the condensation of an interstellar cloud.
9. ________ in Shanghai than in any other city in China.
10. That most natural time units are not simple multiples of each other ________ in constructing a calendar.
11. In the U.S. more than 60 percent of all high school students who ________ continue their education.
12. Although southern California is densely populated, ________ live in the northern part of the state.
13. Waitresses and waiters who serve ________ deserve at least a 20 percent tip.
14. If water is heated to 212 degrees F. ________ as steam.
15. The total production of bushels of corn in the United States is ________ all other cereal crops combined.
16. By the time a baby has reached his first birthday, he should, without the help of an adult, ________ sit up or even stand up.
17. The sport of hang gliding ________ by the Federal Aviation Administration (FAA).
18. It is the recommendation of the U.S. Public Health Service ________ all children be vaccinated against a variety of diseases.
19. Jamestown, the first permanent English settlement in America, ________ in 1607.
20. ________ of the play, 'Mourning Becomes Electra', introduces the cast of characters and hints at the plot.