1.表述：get off one’s back
释义：To stop bothering someone about something.（别再纠缠某人，别再打搅某人）
例句：Would you please get off my back? I'm not going to the interview, and that's final!
My uncle has finally gotten off my back about help him out at the hardware store, thank goodness.
He wanted his mom to get off his back about marriage.
Why don't you get off my back and let me do my work!
2. 表述：give the shirt off one’s back
变异：give someone the shirt off one’s back
释义：To act in a very generous and selfless manner. （不遗余力帮......，尽其所能帮......）
例句：I'm not surprised that Tammy loaned you money—she would give anyone the shirt off her back.
Tom would give any of his old army buddies the shirt off his back.
You can always count on Mark when you're in trouble; he'd give you the shirt off his back.
3.表述：turn one’s back on
释义： To ignore you and refuse to help someone. （拒绝帮助......，对......置之不理）
例句：We appeal to this conference—do not turn your back on the poor.
Our job is to protect children and we can't just turn our backs on them.
She turned her back on her family when she became famous.
After becoming a successful writer, Jim turned his back on all the people he used to know back home.
今天，我们学习了3个雅思语汇：give the shirt off one's back，turn one's back on和an eye for an eye。Hope that you can bear them in mind.