He told his son that one feels pain only when the fruits of labor are wasted.

他告诉儿子，只有当劳动的果实被浪费时，才会感到痛苦。

youdao

Other species take into account the changing conditions of light by performing their visual displays only when the light is favorable.

其他物种只在光线适宜时才会展示它们的视觉形象，以此来考虑光的变化情况。

youdao

In general, your attitudes will be internally consistent only when the behavior is easy, and when those around you hold similar beliefs.

一般来说，只有当行为简单而且周围的人和你有相似的信念时，你的态度才会表现得与内在一致。

youdao

Adults may think they are protecting children from secondhand smoke when they smoke outside their home or only when the children are not there.

VOA: special.2009.01.07

It's one of the only compounds, there's only I think three, where the density actually goes down when it freezes.

它是我见过的，唯一一个，在降温时密度下降的化合物。

麻省理工公开课 - 固态化学导论课程节选

Yeah, run the ball is called, when you run the ball, generally you only do it from 10 yards.

是的，就叫“带球跑”，带球跑的时候，你通常只从十码的地方开始。

美式足球 - SpeakingMax英语口语达人

Only when the shareholder actually sells his own shares is there a taxable event.

FORBES: Capital Idea

The history of Irish republicanism shows that only when the conditions are right can dissident groups take over.

BBC: The IRA's history of splits

Only when the option is exercised does a transaction with tax and bottom-line implications take place.

FORBES: Fact and Comment