$课文17 人为的疾病

237. In the early days of the settlement of Australia, enterprising settlers unwisely introduced the European rabbit.

在澳大利亚移民初期，一些有创业精神的移民不明智地把欧洲兔子引进了澳大利亚。

238. This rabbit had no natural enemies in the Antipodes, so that it multiplied with that promiscuous abandon characteristic of rabbits.

这种兔子在澳大利亚及新西兰没有天敌，因此便以兔子所特有的杂乱交配迅猛繁殖起来。

239. It overran a whole continent.

整个澳洲兔子成灾。

240. It caused devastation by burrowing and by devouring the herbage which might have maintained millions of sheep and cattle.

它们在地下打洞，吃掉本可以饲养数百万头牛羊的牧草，给澳洲大陆造成了毁灭性的破坏。

241. Scientists discovered that this particular variety of rabbit (and apparently no other animal) was susceptible to a fatal virus disease, myxomatosis.

科学家们发现，这种特殊品种的兔子（显然不包括别的动物）易患一种叫“多发性粘液瘤”的致命毒性疾病。

242. By infecting animals and letting them loose in the burrows, local epidemics of this disease could be created.

通过让染上此病的动物在洞内乱跑，就可以使这种疾病在一个地区蔓延起来。

243. Later it was found that there was a type of mosquito which acted as the carrier of this disease and passed it on to the rabbits.