內(nèi)容提要：Hurricanes，即颶風，是一種在大西洋地區(qū)產(chǎn)生的強大熱帶氣旋。它的等級由一到五不等，風速、破化力隨著等級遞增。

Hurricanes are violent windstorms暴風 with a circular movement that carry with them huge amounts of rain. They cause more damage than all other kinds of storms. They form in the warm water areas of the Atlantic Ocean. 

A hurricane begins in a low pressure area over warm water. Air is pulled inward by the low pressure. Wind begins to rotate旋轉(zhuǎn)  counterclockwise逆時針. As pressure drops near the center, wind speed increases. It pulls moist潮濕的 air from the ocean's surface.  The moist air spirals盤旋 upward in the center. The air cools and rainstorms form. This pattern continues as the storm feeds on itself, growing stronger and higher. When the wind speed is greater than 73 m.p.h., it is a hurricane. A column of calm, warm, cloudless air forms in the center. It is the eye of the storm. 

A hurricane can become 10 miles high and 200 miles wide. It travels across the ocean at various speeds. It might change direction several times. That is why it is hard to know when and where it will strike land. It weakens rapidly as it passes over land. 

Hurricanes are rated定級 by categories, depending on their wind speeds. Category種類 Ⅰ means winds are 74-95 m.p.h. The highest category is 5. This means the winds are moving faster than 155 m.p.h. The higher the category, the more damage it causes. 

Hurricanes are given names so weather people can tell them apart when there are more than one over the ocean. On August 17, 1969, Hurricane Camille struck Mississippi and Louisiana. It was a category 5. It caused millions of dollars in damage and 256 people died.

本文內(nèi)容選自上海外語教育出版社引進出版的《聽讀美國小故事》第8冊（8月）。如需購買，可到當當、亞馬遜、京東等網(wǎng)上書城去看看。