✨ ベストアンサー ✨
関係副詞を使って英作文を練習する問題ですね。
1. The place <where this photo was taken> was in front of the Louvre Museum.
2. It is the museum <where you can appreciate the real Mona Lisa>.
3. The first Sundays of October to March are the days <when you are admitted for free>.
※admit … …への入場を許可する for free 無料で
4. That is <how the museum attracts many people from all over the world>.
※That is how+S+V~ そのようにしてSは~する
参考にしてください。