He was zealous for improvement.

他热心于改良。

youdao

He and his descendants will have a covenant of a lasting priesthood, because he was zealous for the honor of his God and made atonement for the Israelites.

这约要给他和他的后裔，作为永远当祭司任职的约，因他为神有忌邪的心，为以色列人赎罪。

youdao

She was a zealous worker for charity.

她是个热衷于慈善事业的工作者。

《柯林斯英汉双解大词典》

Until recently, the education ministry was among the most zealous proselytisers for this system.

ECONOMIST: Japan

Despite complaints by some observers, election officials said the delay was caused by a zealous effort to carefully cross check each result.

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Black students in other Southern towns began to do the same, and lunch counter by lunch counter, drugstore by drugstore, department store by department store, Jim Crow was assaulted by the zealous actions of just a handful of students.

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