What provided one third of the electricity in the United States fifty years ago?

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions from 23 to 30.

Search for alternative sources of energy has led in various directions. Many communities are burning garbage and other biological waste products to produce electricity- Converting waste products to gases or oil is also an efficient way to dispose of wastes. Experimental work is being done to derive synthetic fuels from coal, oil shale, and coal tars. But to date, that process has proven expensive. Other experiments are underway to harness power with giant windmills. Geothermal power is also being tested. Some experts expect utility companies to revive hydroelectric power derived from streams and rivers. Fifty years ago hydroelectric power provided one third of the electricity used in the United States, but today it supplies only 4 percent. The oceans are another potential source of energy. Scientists are studying ways to convert the energy of ocean currents, tides, and waves to electricity. Experiments are also underway to make use of temperature differences in ocean water to produce energy.

Mark the letter A, B, C, or D on your answer sheet to indicate the word(s) CLOSEST in meaning to the underlined word(s) in each of the following questions.

Van Mieu was representative of Confucian ways of thought and behaviors.

Peter said:"I'm sorry. I didn't return the book on time."

Which of the following is NOT mentioned in the passage as an alternative source of energy?

Richards lost his job because he was late every day.

Mark the letter A, B, C, or D on your answer sheet to indicate the most suitable response for each of the following exchanges.

Alfoso: "I had a really good time. Thanks for the lovely evening"

Maria: "­­­­­­____________________."

She always encourages her son ________ harder.

The ____ is the air, water and land in or on which people, animals and plants live.

I’ve to leave for London tomorrow, _______ means I cannot go to the party with you.

Waiter: "May I take your order now, sir?"

The first person ________ the classroom last Monday might know the reason.

What could be best replaced the phrase 'geothermal power' in the passage?

He wouldn't have failed his exam ______ he had been ill.