It has been found that certain bats emit squeaks and by receiving the echoes,

人们发现，某些蝙蝠能发出尖叫声，

Many of these obligations can give rise to problems and complications but a bank customer,

其中许多义务往往引起问题和纠纷。

Almost any day a young porpoise may be seen trying to turn a 300-pound sea turtle over by sticking his snout under the edge of his shell and pushing up for dear life.

几乎每天都可以看到一只小海豚把鼻子顶入一只300磅重的海龟的硬壳下面，拼命地把它翻过来。

he identifies himself with its centre of gravity, its mass, its weight;

他把自身和物体重心、质量、重量融为一体。

the cost of managing and administering the business.

企业行政管理费。

Boiling is always a good way of treating water.

烧开一直是水处理的一种好办法。