Several regions in the world are subject 21______ storms which are so severe that they 22______ damage on a tremendous scale. The regions are all located on the edges of great oceans. The 23______ term for such severe storms is 'cyclone'. The term 'hurricane' is 24______ for storms that occur in the North Atlantic Ocean.
Cyclones(龙卷风) and hurricanes(飓风) differ in one curious 25______: in cyclone,the wind circulates in a clockwise direction; in a hurricane, the wind direction is counter clockwise. 26______ cyclones and hurricanes have one ominous similarity. 27______ 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 28______ mainly in December and January, the summer months in the southern hemisphere.
Usually the Australian cyclones don't cause great damage because Australia's northern territory has vast empty regions that are virtually 29______. There are few coastal cities.When a cyclone 30______ move inland from the sea, it usually blows itself out without striking any inhabited area.
21.