讲解文本：

turn one's back 不愿帮助，抛弃，拒绝，不理睬

Jack turned his back on me when I asked him for help.

当我请求Jack帮助时，他完全不理会。

I can't turn my back on my uncle Steve, he's old and sick now.

我叔叔Steve又老又病，我不能丢下他不管。

疯狂练习吧!