【单选题】

Several regions in the world are subject {{U}} 21 {{/U}} 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 {{U}} 22 {{/U}} term for such severe storms is “cyclone”(龙卷风). The term “hurricane” is {{U}} 23 {{/U}} for storms that occur in the NorthAtlantic Ocean. Cyclones and hurricanes differ in one curious {{U}} 24 {{/U}} : in a cyclone, the wind circulates in a clockwise direction; in a hurricane, the wind direction is counter-clockwise. {{U}} 25 {{/U}} cyclones and hurricanes have one ominous similarity. {{U}} 26 {{/U}} 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 Indonesi

A、The cyclones occur mainly inDecember and January, the summer months in the southern hemisphere.{{U}} 27 {{/U}} theAustralian cyclones don’t cause great damage becauseAustralia’s northern territory has vast empty regions that are virtually unpopulateD、There are {{U}} 28 {{/U}} coastal cities. When a cyclone does move inland from the sea, it usually blows itself out without {{U}} 29 {{/U}} any inhabitated are
A、However, in 1917 the small city of Townville was {{U}} 30 {{/U}} 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.
A、In that
B．In terms of
C．Except for
D．Along with