副詞句(Adverbial phrase)

in which(副詞句) = there(副詞) = where(関係副詞)でもOK
This is the house where he lives in. は間違い
This is the house where he lives. が正しい
関係代名詞すべてthat置き換えが可能

This is the very dictionary ( )I have been look for. ⇒ 目的格の関係代名詞 ⇒ which = that

We have not yet reached the stage (  ) we(S) can make(V) a decision(O) on this matter.(神奈川大学)

( )の後ろは完全 ⇒ 関係代名詞は入らない! ⇒関係副詞か前置詞+関係代名詞が入る。
1. which   2. of where   3. to where    4. where