問題詳情

According to scientists, frogs are disappearing from the earth. Since 1997, the frog population has 46___ two percent every year. Some frog species have completely ___47___. No one can besure why this is happening, but a number of scientists are looking into it. Joe Pechmann, a professor at theUniversity of New Orleans, has been studying frogs for 18 years. He believes there are several stresses onour planet that are killing off frogs. These problems ___48___ pollution, global warming and loss of thefrog habitat due to human population growth. Pechmann warns the loss of frogs should be taken seriously.“It makes sense in theory that what happens to frogs will happen to us,” he said. Even if we aren’t at___49___, we may have to take ___50___ for the extinction of frog species that have managed to survivefor millions of years before man.
46.
(A) at
(B) for
(C) with
(D) by

參考答案

答案：D
難度：適中0.636364
統計：A(0),B(0),C(3),D(7),E(0)

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