Lie flat and let your knees bend.

平躺曲膝。

《牛津词典》

You need to touch your knees!

你要碰到自己的膝盖！

youdao

Follow me, bend your knees.

跟我做，弯曲你的膝盖。

youdao

If you're an oil rich country today, as long as that oil lasts, you got the world kind of at your knees.

如果你今天是富油国,并且能保持稳定的产油量,那整个世界都会匍匐在你的跟前

耶鲁公开课 - 美国内战与重建课程节选

Oh, Son. Did you not ever go on your knees and pray for deliverance from all your sins and scoundrel's acts? Lost boy, depart.

噢，儿子！你怎么不跪下，为了对你的所有,罪恶和卑鄙行为的判决而祈祷，迷失的孩子，走吧。

耶鲁公开课 - 1945年后的美国小说课程节选

First I go over the physical posture you should have because when you're sitting like we usually sit on the round cushion or the floor, re free of contact with people usually both your knees and your butt are for the kneeling.

首先理顺应有的身体姿势,因为打坐时,像我们常会坐在圆坐垫,或地板上，你要确定自己身旁不要有人，you，make，sure，you‘,通常两膝和臀部都要注意,都要碰到地面。

普林斯顿公开课 - 人性课程节选

Getting out of a car with your knees together is still for the ladies only, though.

ECONOMIST: The new interest in etiquette crosses gender boundaries

You need your knees replaced, and you have a choice of two venues.

FORBES: Hospitals' Nightmare

Bend your knees and duck down, rolling your head in a 'U'shape under the punch from 'inside' to 'out.

BBC: DEFENCE