We were crawling around on all fours.

我们匍匐着四处爬行。

She crawled on all fours over to the window.

她匍匐着爬到窗边。

The horse jumped the stream and landed on all fours.

那匹马跳过小溪，四脚落地。

He is just a baby on all fours.

他只是一个匍匐爬行的婴儿。

A baby crawls on all fours.

婴儿四肢着地爬行。