Volcanoes are the ultimate earth-moving machinery. Eruptions have rifted continents, raised mountain chains, constructed islands

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问题     Volcanoes are the ultimate earth-moving machinery. Eruptions have rifted continents, raised mountain chains, constructed islands and shaped the topography of the earth. The entire ocean floor has a basement of volcanic basalt.
    Volcanoes have not only made the continents, they are also thought to have made the world’ s first stable atmosphere and provided all the water for the oceans, rivers and ice-caps. There are now about 600 active volcanoes. Every year they add two or three cubic kilometers of rock to the continents. Imagine a similar number of volcanoes smoking away for me last 3,500 million years. That is enough rock to explain the continental crust.
    What comes out of volcanic craters is mostly gas. More than 90% of this gas is water vapor from the deep earth: enough to explain, over 3,500 million years, the water in the oceans. The rest of the gas is nitrogen, carbon dioxide, sulphur dioxide, methane, ammonia and hydrogen. The quantity of these gases, again multiplied over 3,500 million years, is enough to explain the mass of the world’s atmosphere. We are alive because volcanoes provided the soil, air and water we need.
    Geologists consider the earth as having a molten core, surrounded by a semi-molten mantle and a brittle, outer skin. It helps to think of a soft-boiled egg with a runny yolk, a firm but squishy white and a hard shell. If the shell is even slightly cracked during boiling, the white material bubbles out and sets like a tiny mountain chain over the crack—like an archipelago of volcanic islands such as the Hawaiian Islands. But the earth is so much bigger and the mantle below is so much hotter.
    Even though the mantle rocks are kept solid by overlying pressure, they can still slowly ’flow’ like thick treacle. The flow, thought to be in the form of convection currents, is powerful enough to fracture the ’eggshell’ of the crust into plates, and keep them bumping and grinding against each other, or even overlapping, at the rate of a few centimeters a year. These fracture zones, where the collisions occur, are where earthquakes happen. And, very often, volcanoes.
What rhetorical device does the writer used to describe earth?

选项 A、Contrast.
B、Exaggeration.
C、Comparison.
D、Personification.

答案C

解析 推断题。题干问,作者在描写火山时,用了什么修辞手法?原文第四段.关键词“soft-boiled egg”,作者将地球比作鸡蛋,有一层脆的外壳,地幔如蛋清,其核心如蛋黄。可知,应选comparison(对比),尤其指相同之处的对比。选项A,contrast也为对比之意,但指的是不同之处的对比。选项B意为夸张,D意为拟人,均不符合原文。
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