To give you just a couple of examples how fast this has happened, in the mid-'70s, Brazil declared, "We have no Aedes aegypti," and currently they spend about a billion dollars now a year trying to get rid of it, trying to control it, just one species of mosquito.
举几个例子 来看看这种蔓延有多快。 70年代中期，巴西宣称：“巴西没有埃及伊蚊” 如今他们每年要花十亿美元 灭蚊，试图控制蚊子的数量， 仅仅为了一种蚊子。