It has been estimated that the weight of all the insects destroyed by spiders in Britain in one year would be greater than the total weight of all the human beings in the country.

据估计，在英国蜘蛛一年里所消灭昆虫的重量超过这个国家人口的总重量。

It has expanded without any idea of the true nature of the human beings who run the machines,

现代工业发展起来了，却根本没想到操作机器的人的本质。

He showed that the average individual's sleep cycle is punctuated with peculiar bursts of eye-movements,

他指出，平常人的睡眠周期中不时伴有一阵阵奇怪的眼球队活动，

A burst of activity associated with the laying of submarine cables soon confirmed the Challenger's observation that many parts of the ocean were two to three miles deep,

海洋中很多地方可深达两三英里，

unless the parents themselves have been unsatisfactory,

除非父母自身不能令人满意，

The most economical age to capture an elephant for training is between fifteen and twenty years,

捕捉15至20岁之间年龄的大象进行驯练最为经济。