scratch my back的用法和樣例：
例句
- The contract went to a friend of the chief accountant: it's (a case of) you scratch my back and I'll scratch yours.
承包合同批給了總會計師的朋友，(可謂)各有好處、 串通一氣。 - Scratch my back and I'll scratch yours.
[諺]你幫我，我幫你。 - Linda asked Ham to help her with her lesson Ham said, "You scratch my back and I'll scratch yours."
琳達請誨姆幫助她做功課，海姆說：「你幫助我做，我就幫你做。」
