MôN: tiếng anh chọn phương án ( a hoặc b, c, d) ứng với từ có trọng âm chính nhấn vào âm tiết có vị trí khác với ba từ còn lại trong câu

71. a. engine b. wine c. decline d. design

72. a. pleasant b. husband c. secondhand d. important

73. a. pollute b. polite c. possible d. police

74. a. waste b. vast c. Broadcast d. nasty

75. a. emission b. poison c. miss d. boss

Scientists claim that air pollution causes a decline in the world’s average air temperature. In order to prove that theory , ecologists have turned to historical data in relation to especially huge volcanic eruptions. They suspect that volcanoes effect weather changes that are similar to air pollution.

One source of information is the effect of the eruption of Tambora, a volcano in Sumbawa, the Dutch East Indies, in April 1815. the largest recorded volcanic eruption, tambora threw 150 million tons of fine ash into the stratosphere. The ash from a volcano spread worldwide in a few days and remains in the air for years. Its effect is to turn incoming solar radiation into space and thus cool the earth. For example, records of weather in England show that between April and November 1815, the average temperature had fallen 4.5oF. During the next twenty –four months , England suffered one of the coldest periods of its history. Farmers’ records from April 1815 to Decenver 1818 indicate frost through out the spring and summer and sharp decrease in crop and livestock markets. Since there was a time lag of several years between cause and effect, by the time the world agriculture commodity community had deteriorated, no one realized the cause.

Ecologist today warn that we face a twofold menace. The ever-present possibility of volcanic eruptions, such as that of Mt. St. Helens in Washington, added to man’s pollution of the atmosphere with oil, gas, coal and other polluting substances, may bring us increasingly colder weather.

76. It is believed that the earth get colder when ……

a. volcanoes erupt b. the air is polluted by modern man

c. the rays of the sun are turned into space. D. all of the above

77. The effects of Tambora’s eruption were……

a. felt mainly in the Dutch East Indies b. of several days’duration worldwide.