問題詳情

Scientific experiments can sometimes go wrong and when they do the results may range fromthe disastrous to the troubling. One such experiment took place in South America about fifty yearsago. Whether its final consequences will cause serious damage or nothing more than a small troublestill remains to be seen.      The story began in 1956 when an American scientist working in Brazil decided to solve theproblem of increasing the productivity of that country's bees. He imported a very active type of Afri-can bee from Tanzania and mated  (交配)  it with the more easy-going native variety to produce anew kind of bees. The new bees worked harder and produced twice as much honey. It seemed thatProfessor Kerr, for that was the scientist's name, had a total success on his hands.      Then things began to go wrong. For some reason as yet unseen, but perhaps as a result ofsomething in their environment, the new bees began to develop extremely attacking personali-ties. They became bad-tempered and easy to be angry, attacked the native bees and drove themfrom their living places.      But worse was to follow. Having taken over the countryside, the new bees, with their danger-ous stings (叮) , began to attack its neighbours -- cats, dogs, horses, chickens and finally manhimself.                                                               A long period of terror began that has so far killed a great number of animals and about                    150 human beings.     This would have been bad enough if the bees had stayed in Brazil. But now they are on themove, heading northwards in countless millions towards Central and North America, and moving atthe alarming speed of 200 miles a year. The countries that lie in their path are naturally worriedbecause it looks as if nothing can be done to stop them.
56.The results of the South American experiment .
(A) have caused a serious trouble
(B) have proved to be wrong
(C) are not yet certain
(D) are not important

參考答案

答案：C
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)

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