One authority on spiders made a census of the spiders in grass field in the south of England,

一位研究蜘蛛的权威对英国南部一块草坪上的蜘蛛作了一次调查。

and it spread to Britain where wild rabbits are regarded as a pest but where domesticated rabbits,equally susceptible to the disease, are the basis of a profitable fur industry.

这种疾病又蔓延到了英国。在英国，野兔被当作有害的动物，可是家兔是赚钱的毛皮工业的基础，然而家兔同样易感染这种疾病。

It was not forced upon them by the survival competition; they could have caught and lived on prey without using poison, just as the thousands of non-poisonous snakes still do.

毒液不是生存竞争强加给它们的，它们也可以不用毒液捕捉动物而生存，就像今天成千上万的无毒蛇那样。

The remains of plants and animals that lived on land are much more rarely preserved, for there is seldom anything to cover them over.

曾在陆地上生活过的动植物的遗体被保存下来的更为罕见，因为陆地上几乎没有什么东西覆盖它们。

It is the one world in the Solar System that is most like the Earth.

火星是太阳系里与地球最接近的一颗行星。

and should not be put in drinks unless it is known to be safe.

只有知道冰块安全时才能加入饮料。