Japanese macaques, or 'snow monkeys', are highly social animals, with a complex set of relationships between each other. Entrance to the thermal hot springs, which can reach over 40 degrees centigrade, depends upon the social position of the monkey. Only the highest-ranking females and their infants are allowed in.
短语 you scratch my back and I'll scratch yours 字面意思是你抓我的背我就抓你的背，用来表示人与人之间的互通有无的互助关系：你帮我一个忙我就帮你一个忙，相互帮助。
You know, I think we can help each other out here. I'll lend you my car on Friday if you let me borrow your camera for the wedding. You scratch my back and I'll scratch yours.
If you could come and fix my radiators that would be really helpful. I'll do that translation exercise for you if you like. You scratch my back and I'll scratch yours.
在英语中人们常常用 from scratch 这个短语来表示从头开始或从零开始这一概念。
I was writing my essay and forgot to save it. Guess what happened? Yes, the computer crashed and I had to start from scratch. Why does that always happen?!