It was a village in India. The people were poor. However, they were happy. After all, their forefathers (祖先) had lived in the same way for centuries (世纪).

    Then one day, some visitors from the city arrived. They told the villagers there were some people who liked to eat frogs' legs. However, they did not have enough frogs of their own, so they wanted to buy frogs from other places.

    This seemed like money for nothing. There were millions of frogs in the fields around, and they were no use to the villagers. All they had to do was to catch them. They reached anagreementand people sent their children into the fields to catch frogs. Every week a truck (卡车) arrived to collect the frogs and give them the money. For the first time, the people could dream of a better future, but the dream didn't last (持续) long.

    It was not easy to notice (觉察到) the change at first, but it seemed like the crops (庄稼) were not doing so well. It was more worrying that the children fell ill more often, and there seemed to be more insects (虫) around lately.

    The villagers decided that they couldn't just wait to see the crops failing and the children getting weak. They would have to use the money got to buy pesticides (杀虫剂) and medicines. Soon there was no money left.

    Then the people found out the problem. It was the frog. They were not useless. They had been doing an important job—eating insects. Now with so many frogs killed, the insects were increasing (增加) more quickly. They were eating the crops and spreading diseases (传播疾病).

    Now, the people are still poor. But in the evenings they sit in the village square and listen to sounds of insects and frogs. These sounds of the night now have a much deeper meaning.