名 boundary，scope，extent，circles，bound ；

[例句] 凯西·施滕格尔可能是棒球界最有趣的人物。 Casey Stengel was probably the most colorful character in baseball.

[例句] 作为喜剧界的常青树——他的简单淳朴与自然大方无人能及。 A timeless comic actor—his simplicity and his apparent ease are matchless.