难度：***

upright 直立 arise 发生，出现 conspicuous 明显的 suggest 表明

ilium 髌骨 belly 腹部 pelvis 骨盆 anchor 锚定，固定 novel 新奇的

work up 鼓起勇气

But it took him another 12 years to work up the courage to declare that humans evolved, too.

it = to work up the courage to …

但是他用了12年才鼓起勇气宣称人类也是进化来的。

Darwin argued that humans arose from apes. And one of the most profound changes (that) they underwent was turning into upright walkers.

定语从句的关系代词做从句的宾语时，关系代词要省略。上句即省略了”that“

达尔文认为人类的起源是猿。他们经历的一个最深刻的变化是转变为直立行走的人。

Many of the leg muscles we use (that) in walking are anchored to the ilium.

很多我们用于行走的腿部肌肉是固定在髌骨上的。

The bone also supports the pelvic floor, a network of muscles that acts like a basket for our inner organs when we stand up.

髌骨也支撑着骨盆底层，骨盆底层肌肉是一个肌肉网络，它的作用就如同篮子一样当我们站立时，肌肉网络托住我们的内部器官。