英语句子 how they know in which direction to go until they can s

in which=where
of which=whose
所以这句话是 how they know （where）direction to go until they can see familiar landmarks
意思是他们不知道往哪里走直到看到了熟悉的路标
再问： where 在这边做 什么成分?
再答： 状语
再问： direction to go where？
再答： 我想了想，还是in the direction 向/朝...方向 不好意思啦 介词提前是in which direction