[al:新概念英语（四）] [ar:MP3 同步字幕版（英音）] [ti:A Man-made Disease] [by:更多学习内容，请到chazidian.com搜索“新概念”] [00:01.55]Lesson 17 [00:03.76]A man-made disease [00:12.84]What factor helped to spread the disease of myxomatosis? [00:19.81]In the early days of the settlement of Australia, enterprising settlers unwisely introduced the European rabbit. [00:28.27]This rabbit had no natural enemies in the Antipodes, so that it multiplied with that promiscuous abandon characteristic of rabbits. [00:39.36]It overran a whole continent. [00:41.81]It caused devastation by burrowing and by devouring the herbage which might have maintained millions of sheep and cattle. [00:50.85]Scientists discovered that this particular variety of rabbit (and apparently no other animal) was susceptible to a fatal virus disease, myxomatosis. [01:03.19]By infecting animals and letting them loose in the burrows, local epidemics of this disease could be created. [01:11.15]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. [01:20.29]So while the rest of the world was trying to get rid of mosquitoes, Australia was encouraging this one. [01:27.83]It effectively spread the disease all over the continent and drastically reduced the rabit population. [01:35.04]It later became apparent that rabbits were developing a degree of resistance to this disease, [01:41.22]so that the rabbit population was unlikely to be completely exterminated. [01:46.90]There were hopes, however, that the problem of the rabbit would become manageable. [01:53.12]Ironically, Europe, which had bequeathed the rabbit as a pest to Australia, acquired this man-made disease as a pestilence. [02:02.70]A French physician decided to get rid of the wild rabbits on his own estate and introduced myxomatosis. [02:10.22]It did not, however, remain within the confines of this estate. [02:14.71]It spread through France, where wild rabbits are not generally regarded as a pest but as a sport and a useful food supply, [02:23.95]and it spread to Britain where wild rabbits are regarded as a pest but where domesticated rabbits, [02:30.93]equally susceptible to the disease, are the basis of a profitable fur industry. [02:36.90]The question became one of whether Man could control the disease he had invented.