She's an authority on criminal law.

她是刑法专家。

《牛津词典》

He is an authority on corporate law.

他是公司法方面的权威。

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Mutual restriction between the prosecutorial power and the judicial authority in a judicial office is an important link to independently exercise judicial power based on the law.

司法机关内部检察权与审判权的相互制约，是依法独立行使司法职权的重要环节。

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As Paul Redmond Michel, an authority on patent law, points out, these operations will be larger than anything either corporation has in the United States.

FORBES: Globalism and Technology: A Hidden Misconception That Dooms the U.S. Economy

While the new court was still theoretically under the authority of the Supreme Court, the fact that it heard so many patent cases gave it an outsized influence on patent law.

FORBES: As Supreme Court Software Patent Ban Turns 40, It's Time To Stop Ignoring It