✨ ベストアンサー ✨
1. one(代名詞):a/an+単数名詞 を表す
2. it(代名詞):the+単数名詞 を表す
従って、Have you ever seen the koala? → 〇 Yes, I have seen it before. itを選んでいいです❣
では、次の問題の答えはどちらでしょうか?
3. Have you ever seen the koalas? → Yes, I have seen ( ones / them ) before. ( 〇 them )
4. Have you ever seen koalas? → Yes, I have seen ( ones / some ) before. ( 〇 some )
参考にしてください。