to move on the hands and knees 的on是什么意思啊

to move on the hands and knees 的on是什么意思啊

to move on the hands and knees 的on是什么意思啊
1 手和膝盖
he tried again and again , and then contented himself with crawling about on hands and knees .他试了又试，后来只好用手和膝盖爬来爬去。
2 用手脚
the hole was so small that he had to crawl on hands and knees to pass through it .这个洞非常窄小，因此他必须用手脚爬过去。
3 伏在地上
高一英语新教材(下)词组总汇(13-22) ...on hands and knees 爬着，匍匐着, 伏在地上self rescue 自救

搜一下：to move on the hands and knees 的on是什么意思啊