refine ·verb
Definition: to improve an idea, method, system, etc. by making small changes Level: C2
工程师们花了几个月时间改进软件。
The engineers spent months ___refining the software.
Zucchero Fornaciari 十年前在一个全国性节目中被发现，在这段时间里，他磨练并完善了他的音乐。
Zucchero Fornaciari was discovered ten years ago in a national show and during this period of time has sharpened and ___refined his music.
科学家们不断根据新证据改进他们的理论。
Scientists are constantly ___refining their theories based on new evidence.