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TOEFL Preparation: Lesson 8 - Energy

Updated: Aug 8, 2022

Target Words 1. combustion

2. component

3. convey 4. discretely 5. nucleus 6. permeate

7. rotate 8. solar 9. source 10. trigger

Definitions and Samples

1. combustion n. The process of burning When air quality is poor, combustion of materials in a fireplace is prohibited. Usage tips Combustion is often followed by of.

Parts of speech combust v, combustible adj

2. component n. One part of a system or whole Their home theater system has a number of separate components. Usage tips Component is often followed or preceded by of.

3. convey v. To transport from one place to another; to transmit or make known A messenger conveyed the prince’s letter to the commander of the army. The worst part about being a doctor was when she had to convey bad news to a family. Parts of speech conveyance n, conveyor n

4. discretely adv. Separately; distinctly In order to understand how the engine worked, each component needed to be studied discretely. Parts of speech discrete adj

5. nucleus n. A central or essential part around which other parts are gathered; a core The nucleus of many European cities is the town square. Usage tips Nucleus is often followed by of. Parts of speech nuclear adj

6. permeate v. To spread or flow throughout;to pass through or penetrate

The smell of cooking permeated the entire apartment building. Parts of speech permeation n

7. rotate v. To turn around; to take turns in sequence The planet rotates on its axis once every 14 Earth days. The children rotate classroom responsibilities on a weekly basis. Parts of speech rotation n

8. solar adj. Of, or relating to, the sun The ancient society kept time with a solar calendar.

9. source n. The point of origin or creation The reporter was unable to identify the source of the information for his story.

Parts of speech source v 10. trigger v. To set-off or initiate I was certain any mention of politics would trigger a big argument. Parts of speech trigger n


Complete each sentence by filling in the blank with the best word from the list. Change the form of the word if necessary. Use each word only once. combustion convey permeate source trigger

  1. It is often difficult to __________ the meaning of a poem to a large audience.

  2. The __________ of the gossip was someone inside this office.

  3. Her bad mood that day __________ the atmosphere in the laboratory.

  4. The internal __________ engine revolutionized the way automobiles run.

  5. A cigarette __________ the explosion.


Match the word that is closest in meaning to each word or phrase in the right-hand column. 1. rotate (a) separately, as an individual part 2. solar (b) spin on an axis 3. component (c) sun

4. discretely (d) center

5. nucleus (e) part TOEFL Success

Read the passage to review the vocabulary you have learned. Answer the questions that follow.

Most of the electricity in the United States is produced in steam turbines. There are many discrete steps in this process. In a steam turbine, combustion of coal, petroleum, or natural gas heats water to make steam. The steam rotates a shaft that is connected to a generator that produces electricity. Finally, that electricity is converted by a transformer and conveyed from the turbine to its place of use. Many sources can provide energy to heat the water in a steam turbine. Coal is primary, producing 51 percent of the country’s electricity. Another common way to heat water for steam turbines is through nuclear power. In nuclear fission, atoms of uranium fuel are hit by neutrons, triggering a continuous chain of fission that releases heat. In 2001, nuclear power generated 21 percent of the electricity in the United States. Solar power produces less than 1 percent of the United States’ electricity needs, because it is not regularly available and harnessing it is more expensive than using fossil fuels. Dependence on electricity permeates daily life in the United States. Still, few people are aware of the many components of electricity production.

1. What does the author say about solar power?

  1. It produces more electricity than any other source.

  2. It is a relatively small source of energy for heating water in steam turbines.

  3. Electricity producers are trying to use it more regularly.

  4. Researchers are trying to make it cheaper to use.

2. In the passage, the word transformer probably refers to a

a. truck b. generator that produces electricity

c. type of turbine d. device that changes electric currents

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