"A field of knowledge" 是 "一门学问" 的英语表达方式。
来源：这是一个通俗易懂的说法，表示一个研究领域或一个学科。
例句：
Mathematics is a field of knowledge that deals with numbers and their properties.
(数学是一门处理数字和它们属性的学问。)
Philosophy is a field of knowledge that explores the nature of existence, reapty, and knowledge.
(哲学是一门探索存在、现实和知识本质的学问。)
Biology is a field of knowledge that studies pving organisms and their interactions with each other and their environment.
(生物学是一门研究生物体及其相互作用和环境的学问。)