查過Longman - man who would work in an art gallery
Cambridge – an art teacher.
Dictionary.com Dance is an art.
art 之前的冠詞確實是an
但在yahoo 英文網 a art 用的幾乎到了和
an art 一樣普遍,若說他們亂寫,An FBI agent 及 An MBA 幾乎沒人寫錯,所以感
覺上有點怪!另這位畫家website, 內文也是用a art gallery,我覺得她不太可能用錯字。