阅读理解

　　Volcanoes trigger(引发) strange weather. Mount Tamora's 1815 eruption near Java made enormous effect on weather. Summer crops in France failed, causing food shortages. On the east coast of the U. S., it snowed in June, and in July many people in the normally hot American South awoke to find their fields white with frost. The cold touch of a volcano's hot breath made 1816 what came to be called “the year without a summer”.

　　According to current theory, heat welling up from within the earth forces geologic movements of continents and triggers volcanoes. However the upwelling of heat from deep beneath us keeps Earth alive. For one thing, wither would wear away the land. Second, rainfall is constantly washing key elements of life, such as carbon and sulfur, into the world's oceans.

　　Volcanic eruptions bring about other surprising consequences(结果). Despite the risk of future explosion, volcanic regions attract farmers because crops grow wonderfully in their mineral-enriched soils. The Antarctic volcano Mount Erebus dusts the white continent with microscopic particles(微小的颗粒) of pure gold when it erupts. And volcanic conduits called kimberlite[金伯利岩(常含钻石)] pipes in southern Africa and Siberia become depositories(储藏) for diamonds squeezed(从……中获取的) from carbon in the fieryroots of volcanoes.

　　American, British, French and German scientists are developing and testing something called Hot, Dry Rock(HDR) technology. “This technology could offer clean, reliable(可靠的), cheap energy to billions of people around the world,” says Los Alamos HDR Program Manager David Duchane, “and it's under our feet right now.”

1．The 1816 food shortages in France are believed to have resulted f from ________.

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A．the extreme cold weather all over Europe in 1815

B．the frost in southern American states in July, 1816

C．the snowing on the east coast of the U. S. in June, 1816

D．the volcanic eruption of Mount Tambora in 1815

2．From the passage, we know that frequent volcanic eruptions are caused by ________.

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A．the raging heat from within the earth

B．unbalanced global weather changes

C．geologic movements of continents on Earth

D．the human-created atmospheric heat that envelops our planet

3．Farmers may go and work in the volcanic regions because ________.

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A．they find nowhere to settle down for farming

B．the soil there promises better yield

C．they are curious about volcanic eruptions

D．they are entirely ignorant of the risk of future eruption

4．The HDR technology ________.

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A．is not only inexpensive but also applicable(能应用的) everywhere

B．provides cheap energy but its use is limited to volcanic regions

C．taps geothermal-energy and makes water clean

D．promises an ideal substitute for any forms of energy now in use