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小朋友,你知道圣海伦斯火山吗?它是位于美国华盛顿州的一座活火山。1980年的5月18日,休眠了123年的它突然喷发。这表明它从睡梦中醒来了。这到底是怎么回事呢?原来:1980年3月20日,圣海伦斯火山经历了一场里氏4.2级的地震。3月27日,烟雾开始从火山口冒出。到4月末的时候,圣海伦斯火山的北面开始凸起及膨胀起来。5月18日,在毫无先兆的情况下,圣海伦斯火山经历了第二次地震,强度为5.1级。随之,“轰”的一声巨响,圣海伦斯火山喷发了!只见在滚滚浓烟中,一朵巨大的火山烟云冲向两万米高空,遮住了太阳,瞬间白昼变成了黑夜;炙
Children, do you know Mount St. Helens? It is an active volcano located in Washington State. On May 18, 1980, it erupted suddenly for 123 years. This shows that it woke up from its sleep. What happened? The original: March 20, 1980, St. Helens volcano experienced a magnitude 4.2 earthquake. March 27, the smoke began to emerge from the crater. By the end of April, the north of Mount St. Helens began to bulge and expand. On May 18, without any warning, St Helens volcano experienced a second earthquake with a strength of 5.1. Followed by, “boom ” a loud noise, St Helens volcano erupted! I saw billowing smoke, a huge volcanic cloud of smoke rushed twenty thousand meters high, covering the sun, the moment the day becomes The night; Sunburn