A lot of people find it useful to have a phrasebook when they travel to a country they don

问题补充：

A lot of people find it useful to have a phrasebook when they travel to a country they don’t know the language．

A. where

B. when

C. why

D. which

答案：

(答案→)A. where

B. when

C. why

D. which

解析：考查定语从句。句中先行词为country，在定语从句中作地点状语，故用关系副词where，选A。