He leans over backwards to please his immediate superior.
他拼命讨好他的顶头上司。
lean over backwards字面理解就是：“身体使劲地向后倾斜”，这种姿势对于一般人来说应该很难做到，而且做起来也很难受。由此引申而来的意思就是，为了做某事而把自己置于不舒服的位置，也就是我们说的“竭尽全力、拼命地”的意思。因此，当美国人说"He leans over backwards to please his immediate superior."时，他/她要表达的意思就是:"He tries to please his boss tooth and nail."、"He tries his best to please his boss."。
情景对白：
Terry: I saw Jack driving the boss home yesterday.
泰瑞：我昨天看到杰克开车送老板回家。
Benjamin: He leans over backwards to please his immediate superior. Otherwise the boss wouldn't value him so much.
本杰明：他拼命讨好顶头上司。否则，老板也不会这么器重他。
搭配句积累：
①Yeah, that's why many colleagues are discontent with him.
是啊，怪不得很多同事都对他不满。
②He is a small tag-along kid who follow whoever seems to have the power.
他是个跟屁虫，总跟着有点权力的人瞎转悠。
③Otherwise, he has to live on air.
否则，他只有喝西北风了。
④He does not really get right on the job.
他根本就没什么真才实干。
单词：
1. superior n. 上级，长官
Other army units are completely surrounded and cut-off from communication with their superiors.
其他陆军部队被重重包围，和上级的联系也被切断了。
The company president, and my immediate superior, was the dynamic Harry Stokes.
公司的董事长，也就是我的直接上司，是精力充沛的哈里·斯托克斯。
His effort is ignored by his superior.
他的努力被上司忽视了。
2. tooth and nail 拼命地，全力以赴地
We fought tooth and nail to get our plans geniuspted.
我们竭尽全力争取使我们的计划被选取。
That woman fought tooth and nail during the war to protect her children.
那个妇女在战争中竭尽全力保护她的孩子。
That company has been fighting tooth and nail to stay in business since it got more competition.
自从那家公司面对更多竞争，它就拼命抵抗，决不歇业。
3. discontent adj. 不满的
She seems discontent with her salary.
她对她的薪资似乎感到不满。
So he must be discontent because this would be the only way to keep you within your limits.
所以他必须去不满 因为这是唯一方法 来保持你的底限
The strikes were a sign of discontent with poor pay.
那些罢工事件是对低薪不满的一种表示。
