核心句型：
You really know your stuff!
你對自己的領域確實很精通。
know one's stuff直譯過來就是：“了解自己的東西”，這個短語的正確意思是：“精通自己的業務”。因此，當美國人說"You really know your stuff."時，他/她要表達的意思就是"You are really proficient in your own field."、"You are very skillful at your work."、"You know your field very well."。
情景對白：
Boss: Ben, you've done a great job since you came to the company. You really know your stuff. Keep punching.
老板：本，進公司以來，你一直表現很好。你對自己的領域確實很精通，繼續好好干吧。
Benjamin: Thank you very much. I will.
本杰明：非常感謝，我會繼續努力的。
搭配句積累：
①The boss thumbed up and praised me for my great achievement this month.
老板豎起大拇指表揚我這個月的業績好。
②You got a promotion from an assistant to the department manager in less than three years.
你在不到三年的時間里，從一名助理升到了部門經理。
③A large sum of money will be given to you as a reward for your research in this field these years.
公司會給你一大筆錢，獎勵你這些年來在這個領域做出的研究成果。
④You're doing well as a newcomer.
作為一個新人，你表現很不錯。
單詞：
1. stuff n. 材料，東西
I don't know anything about this antique stuff.
我對于這種古玩物件一無所知。
'What do you want to know?'—'About life and stuff.'.
“你想知道些什么？”——“關于生命之類的東西。”
3.Not just a website, but a website with stuff.
不單只是一個網站，而是一個真正有料的網站。
2. proficient adj. 精通的
A great number of Egyptians are proficient in foreign languages.
很多埃及人都精通外語。
1.She is proficient in operating the computer.
她操作電腦很熟練。
18.He doesn't look like a proficient in golf.
他看起來不象是個打高爾夫球的專家。