英语语音和省力原则密切相关.

English Pronunciation is closely associated with the Principle of Least Effort.

这是最新发明的省力装置.

That is the last thing in labour - saving devices.

从泉中担水上山,就省力多了.

This made the work of fetching water up the hill much easier.

给一个支点能够省力的简单机械。

That gives a mechanical advantage when given a fulcrum.

阅读书籍要比叙述其内容更省力。

The book is more easily read than described.

启闭迅速，操作灵活，轻便省力。

Quick Open-Close Operation, Fixable Operation, Simple and Easy.

自动化省时省力。

Automation reduces time and effort.

槽刀采用锯齿形设计刀片, 省力耐用.

The blade of groove is designed with sawtooth, saving effort and durable.

分别用图解法和函数解析法讨论斜面是否省力问题，只有满足一定的条件时斜面才会省力。

With the help of both graphic method and functional analytic solution, the author figures out that only under some certain circumstances can energy be saved on an oblique plane.

吃浮游生物的蝠鲼也是用最省力的方式在水中滑翔。

Plankton feeding rays do so, gliding with minimum effort.