boundary 
英 [ˈbaʊndərɪ]  美 [ˈbaʊndəri] 
n. 边界，分界线；范围

例句：
the Bow Brook, which forms the western boundary of the wood 

构成树林西部边界的鲍溪

Drug traffickers operate across national boundaries. 

毒贩进行跨国贩毒活动。

The boundaries between history and storytelling are always being blurred and muddled. 

历史和说书的界线一向是模糊不清的。

extending the boundaries of press freedom 

扩大新闻自由的范围