So they did. They divided Northern Alabama into 11 zones, and within three years, about 100 dollars per house, they mosquito proofed every house.
他们这么做了。他们把北阿拉巴马分成了11个区域， 并且在三年内，每所房子花费大约100美元， 他们对每所房子都进行了防蚊处理。