在北极,生活着一种叫旅鼠的草食小动物。它们个头虽小,繁殖力却超级强悍,一对旅鼠夫妇一年可以生育七八次,每胎最多可以生二十只幼崽,而且幼崽在二十天内便可发育成熟、繁衍生育。也就是说,一对成年旅鼠夫妇,一年便可繁殖出几十万只后代。超级强悍的繁殖能力,给旅鼠种族带来的最严重威胁就是:每隔三四年,北极上的旅鼠数量就会爆发到顶峰,达到北极所能供养旅鼠数量的极限。如此数量巨大的旅鼠在短期内便可将北极的可食之 In the North Pole, life is a kind of herbivores called lemmings. Although they are small in size and fertility is super tough, a pair of lemmings can be fertile seven or eight times a year, each child can have up to 20 pups, and cubs can mature in 20 days, multiply fertility. In other words, a couple of adult lemmings, a year can breed hundreds of thousands of offspring. The most serious threat to the lemmings raccoon from the super-tough breeding ability is that every three or four years, the number of lemmings on the Arctic peak to the limit where the Arctic can feed its lemmings. Such a huge number of lemmings in the short term can be edible Arctic