每年要发生100多万次地震。但其中大多数地震都因为太小而未引起注意。地震可能发生在地上,也可能发生在水下。一次大的地震可能只延续一分钟,但是在这个时间里它可能使成千上万的人丧生,使许多城镇和乡村毁于一旦。 1906年4月18日凌晨,一次历史上最著名的自然灾害突然发生了, More than 1 million earthquakes occur each year. However, most of these earthquakes were too small to attract attention. An earthquake may occur on the ground or it may occur underwater. A large earthquake may last only one minute, but it may kill thousands of people during this time, destroying many towns and villages. In the early morning of April 18, 1906, the most famous natural disaster in history suddenly occurred.