This is just like the pet cart in the book you borrowed from the library.
It's the same thing that we saw in the book you borrowed from your friend.
この場合、次のような言い方ができますよ。
ーThis is just like the pet cart in the book you borrowed from the library.
「あなたが図書館で借りてきた本に載っていたペットカートのようだね」
halさんの英文は、次のように言うともっと自然な言い方になりますよ。
ーIt's the same thing that we saw in the book you borrowed from your friend.
「あなたが友達から借りてきた本で見たものと同じだね」
ご参考まで!
It's similar to what we saw in the book you borrowed.
It's the same thing as what we saw in the book you borrowed.
ご質問ありがとうございます。
・「It's similar to what we saw in the book you borrowed.」
「It's the same thing as what we saw in the book you borrowed.」
(意味) あなたが借りてきた本で見たものと同じだ
<例文>It's the same thing as what we saw in the book you borrowed.// You're right!
<訳> あなたが借りてきた本で見たものと同じだ。//本当だね!
参考になれば幸いです。