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Originally, the interior of the earth is filled with hot magma. Under tremendous pressure, the hot magma will break through the earth's crust and spouts out, causing the volcano. 原来,地球内部充满了热的岩浆。在巨大的压力下, 滚烫的岩浆会冲破地壳,喷出,造成火山。
Flash floods occur suddenly due to rapidly rising water along a stream or lowlying area. 山洪突然出现是由于迅速上涨的水沿着小溪或低 洼地区奔流而下。
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How does a typhoon happen?
When lots of sea water gets hot in the summer sun, it evaporates(蒸发)into the air.This makes the air hotter. When the air gets warm enough,it starts to move higher up into the sky. Then,cooler air around it rushes in.It fills the space that is left. After the air gets warmer, it starts to move quickly,making wind. The wind goes in circles, and it keeps moving higher in the sky. The warmer the air gets, the quicker the wind moves. And when the wind moves faster than 30 meters a second, a typhoon begins.