雅思阅读材料：越来越少见的雾_雅思英语阅读

雅思阅读材料：越来越少见的雾

　　随着城市化的进一步加剧，雾这种自然现象变得越来越稀少，回想一下，你上次见到雾是什么时候?想不起来了吧。即使是居住在非常潮湿的地方，雾也变得越来越少，这是为什么呢?我们来看下面的雅思阅读材料。

　　When was the last time you saw a frog? Chances are, if you live in a city, you have not seen one for some time. Even in wet areas once teeming with frogs and toads, it is becoming less and less easy to find those slimy, hopping and sometimes poisonous members of the animal kingdom.

　　All over the world, and even in remote parts of Australia, frogs are losing the ecological battle for survival, and biologists are at a loss to explain their demise. Are amphibians simply oversensitive to changes in the ecosystem? Could it be that their rapid decline in numbers is signaling some coming environmental disaster for us all?

　　This frightening scenario is in part the consequence of a dramatic increase over the last quarter century in the development of once natural areas of wet marshland; home not only to frogs but to all manner of wildlife. However, as yet, there are no obvious reasons why certain frog species are disappearing from rainforests in Australia that have barely been touched by human hand.

　　The mystery is unsettling to say the least, for it is known that amphibian species are extremely sensitive to environmental variations in temperature and moisture levels. The danger is that planet Earth might not only lose a vital link in the ecological food chain , but we might be increasing our output of air pollutants to levels that may have already become irreversible. Frogs could be inadvertently warning us of a catastrophe.