Native to America, the cane toad (癞蛤蟆) was introduced to northern Queensland 70 years ago to control sugarcane beetles (甘蔗害虫). The toads failed in that duty but spread across Queensland and into neighboring northern area.

Now it calmly invades(侵略)the states of Western Australia and New South Wales (NSW). NSW wildlife experts fear the amphibians--which have poisonous backs that kill hungry predators,(食肉动物)--will have a terrible effect on native animals.

Those fears may be about to be realized. Australia’s leading government research body, the  Commonwealth Science and Industry Research organization (CSIRO), forecasts a rise in average temperatures that will make NSW ideal living place for the cane toad.

Tony Robinson, head of CSIRO’s Wildlife,Pests,and Diseases Program, said climate change is increasing the amount of suitable living place for the toad.

“With climate change, the cane toads might go down as far as Sydney and some areas of Western Australia,” Robinson said.

Recent estimates put the pace of the toad’s westward march at nearly 17 miles(27 kilometers)a year and slightly slower from north to south.

More southerly cities, such as Melbourne and Adelaide, would likely remain too cold and dry to ever suit the toads, Robinson noted, but Perth could expect cane toads in five years’ time.

Sydney could see their arrival in the next 20 years.

Robinson said there is no 0ne method that will keep the toads under control.

The cane toads already cover at least half of Queensland and most of the northern country the toads are believed to number in the billions.

A Venezuelan virus was tried in the 1990s but had to be given up after it was found to also kill native frog species.

Scientists and governmental bodies believe a national approach is needed.

The main threat the toads cause to species such as dingos, quolls, goannas, and crocodiles is the poison contained in glands (腺) on each of the frogs' shoulders. The poison sprays out when the toads are threatened or handled roughly.

The poison is made up of 14 different chemicals. Together they cause rapid heartbeats, excessive salivation, convulsions, and paralysis.

Cane toads also compete, and usually win, the hunt for food and living space.

“If the government and other states combine resources, I believe we can achieve a very practical biological -control research program, ”Burns said.

72.Which of the following can be the best title of the passage?

       A.Poison Toads Leap Across Australia

       B.Strategies To Keep the Toads Under Control

       C.The Main Threat the Cane Toads Cause

       D.Climate Favours the Spread of Cane Toads.

73.According to the passage, which of the following is true about the cane toads?

       A.The cane toads are strong enough to kill dingos, quolls or even crocodiles.

       B.With 14 different kinds of poisons in its body, a cane toad always wins the hunt for food.

       C.The cane toad was brought to Australia to kill pests from America 70 years ago.

       D.The toads move westward and northward because there is plenty of food there.

74.It can be inferred from the passage that          .

       A.The cane toad bites its enemy dead when it is threatened or handled rudely.

       B.The cane toad has already threatened the survival of the native species.

       C.Scientists and governmental bodies have achieved a successful biological - control

program.

       D.The cane toad likes warm and wet weather.

75.The underlined words “the amphibians” in the third paragraph mean          .

       A.hungry predators                                B.sugarcane beetles

       C.the cane toads                                                     D.dingos

 

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