Several regions in the world are subject 21_______ storms which are so severe that they cause damage on a tremendous scale. The regions are all located on the edges of great oceans. The 22_______ term for such severe storms is “cyclone”(龙卷风). The term “hurricane” is 23_______ for storms that occur in the North Atlantic Ocean.
Cyclones and hurricanes differ in one curious 24_______ : in a cyclone, the wind circulates in a clockwise direction; in a hurricane, the wind direction is counter-clockwise. 25_______ cyclones and hurricanes have one ominous similarity. 26_______ the damage they cause on land and at sea， they are identical.
Australia undergoes a number of cyclones every year along its northern coast, which faces Indonesia. The cyclones occur mainly in December and January, the summer months in the southern hemisphere.
27_______ the Australian cyclones don’t cause great damage because Australia’s northern territory has vast empty regions that are virtually unpopulated. There are 28_______ coastal cities. When a cyclone does move inland from the sea, it usually blows itself out without 29_______ any inhabitated area. However, in 1917 the small city of Townville was 30_______ devastated by a cyclone. There was a public outcry about it. People demand an adequate warning system. Ever since then the meteorological bureau has regularly issued alarms in advance of every serious cyclone.
23.