英语翻译all the members of the tribes knew what was required of

英语翻译
all the members of the tribes knew what was required of them by life long familiarity with the task of the area

所有的部落成员都知道在这个地方生活一辈子、劳作一辈子对他们的适应能力有怎样的要求.
tribe 部落.
familiarity 是 familiar 这个形容词的名词形式.熟悉程度,适应程度,达尔文所说的“适应环境”.be familiar with 是习惯搭配,所以 familiarity with blablabla.就是对blablabla的适应程度.
task ,名词的释义第2项是.a difficult or tedious undertaking.困难艰巨的事情.任务.我翻译为劳作.
what was required of them by life long familiarity with the task of the area
= what of them was required by (...) familiarity (...) 他们自身的哪些东西是被“熟悉程度/适应性”所要求的,（由于“熟悉程度/适应能力”提出了要求而必须具备的）
至于为什么是那个familiarity“熟悉程度/适应能力”对原始人来说是很高要求,因为这个familiarity 是对于the task of the area,这个地儿的重重挑战向原始人提出了要求,而且这是一个一辈子的事情life long （名词作副词形容long 漫长的）+ familiarity,不断受挑战,不断适应,适应就是familiarity.
那么,原始人所了解的就是这些what is required by a familiarity.
all the members of the tribes是主语
knew是谓语
what was .of the area是宾语
在这个宾语从句中：what 是被动式形式主语
was required 是谓语
by life long familiarity with the task of the area是谓语的实际主语.be+动词过去分词+by+主语 被动结构