There was nothing strange really: they themselves were sufficient cause.

其实一点儿都不奇怪，他们本人就是充足的推动力。

youdao

Neither party shall cancel the contract without sufficient cause or reason.

双方均不得无故解除合同。（如果译成“…没有原因和理由”的话，就不够精炼。）

youdao

Although the agent must be present for a disease to occur, it alone is not a sufficient cause.

虽然疾病发生是必须有病原存在，但病原存在并不是唯一的原因。

youdao

He actually recognized and, of course, many people recognized that this jellyfish was fluorescent, and he isolated the actual protein, and determined and proved that this protein was sufficient to cause this fluorescence.

他认识到了，当然，很多人都认识到了水母是有萤光的，它分离出了这种蛋白质，测定了它并证明,这种蛋白质会导致萤光。

麻省理工公开课 - 化学原理课程节选

But is a questionable hypothesis sufficient cause for a federal investigation of a federal scientist?

FORBES: Drowning Polar Bears And the Return Of Ursus Bogus

Anyone on of those three being sufficient cause to simply ignore them.

FORBES: Solving Climate Change

This in itself is sufficient cause for Merz and Metz to hang.

CNN: After 63 years, vet learns of brother's death in Nazi slave camp