interests

當 interest 解作「興趣」的名詞時, 是「可數」的 (Countable).
因此, 它可以是眾數, 也可以是單數. 例如:

My INTERESTS include swimming, cycling and reading.
I have AN INTEREST in Chinese chess.

2006-11-10 15:11:37 補充：
yahoo 字典已有很多例子可以供你參考:1. 興趣;關注;愛好[C][U][( in)]I developed an interest in the machine.我對這機器發生了興趣。I have lost my interest in chemistry.我對化學已不感興趣。2. 趣味性[U][( to)]Local color added interest to the novel.地方色彩增加了這部小說的趣味性。

2006-11-10 15:11:58 補充：
3. 感興趣的事物或人[C]His two great interests in life are music and painting.他生活中的兩大興趣是音樂和繪畫。4. 利益;利害;同業;同行[P1]We work for our common interests.我們為共同的利益而工作。5. 利息[U]I borrowed the money at 5% interest.我以五分利息借了那筆錢。