Hares and Rabbits
One of the gentlest of all animals is the hare. When you consider how mild this animal is, you might wonder how it can survive in a world full of enemies. But then you've also probably noticed its strong hind（后面的）legs. Those legs give it plenty of speed. And you know how rapidly hares and rabbits breed（繁殖）. That’s another reason why they manage to survive.
Hares and rabbits have long, sharp front teeth. Their hind legs are longer than their front legs so that they run faster uphill than downhill. When they are hunted, they use tricks such as taking huge leaps to break the smell or signal danger to each other by hitting the ground with their hind feet. Hares and rabbits are purely vegetarians（素食者）. They can live very well on the inner bark f trees.
There are many differences between hares and rabbits. Hares are larger, and their feet and ears are longer. Hares do not dig holes or live in groups, as do rabbits. Hares are born pen-eyed and with thick fur, while rabbits are born blind and hairless.
North America is the home of many different types of hares. One of the best known is the jack hare, a large hare with very long ears. Jacks are so fast that they can sometimes make a leap of six meters.
The March hare, whom we know from Alice in Wonderland, is a common European hare. In March, they are always busy in mating, thus acquiring its name.
Unlike hares, rabbits are social animals, living together in holes. A rabbit may mate when it is six months old and its young are born within a month. So if the rabbit has no natural enemies, it can become quite a pest.
Rabbits' natural enemies prevent them from_____.
A、becoming a big trouble
B、breeding when young
C、living in holes
D、becoming social animals
【正确答案】：A
【题目解析】：推理判断题。由最后一段最后一句可知，如果家兔没有天敌的话，它就会泛滥成灾了。所以正是家兔的天敌阻止它们成为大麻烦。故选A。
