今天在学英语的时候看到一个句子

It's all for a good cause.

乍一看可以理解为“都是很好的原因”但是以联系上下文觉着好像不对。索性查了字典才发现原来cause除了“原因”这个意思。还可以用作名词“事业”来解释，以下是词典例句

Refusing to have one leader has not helped the cause.

拒绝推举一名领导者对此项事业毫无帮助。

Campaigners hope that people will be sympathetic to their cause.

活动家们希望人们同情支持他们的事业。

He has championed (=strongly supported) the cause of renewable energy since the mid-1970s.

他从20世纪70年代中期开始就积极支持可再生能源事业。

Please give as much as you can: it’ s for a very worthy cause.

请尽力捐赠：这是为了一项很崇高的事业。

It may be hard work but it’ s all in a good cause.

工作可能很苦，但这一切都是为了正义的事业