I'm aiming for the kneecaps!

我正在瞄准他们的膝盖骨！

Babies are born without kneecaps.

婴生下来时是没有膝盖骨的.

I still got the kneecaps from the last one who tried.

最近一次想这么做的人，他的膝盖骨还在我这里呢。

When skiing, you should wear the protecting equipments such as the snow clothing, gloves, kneecaps and masks.

滑雪者在滑雪时应穿滑雪服、佩戴滑雪手套、护脸、护膝等护具。

Now, we take a deep breath in, and on an exhale, I engage the core, I wake up my center by lifting the kneecaps.

现在我们深吸一口气，然后呼气，我锻炼了核心部分，并通过抬起膝盖来唤醒自己的中心。