Question

for many people ,the best friend becomes a brother or a sister they'd always

Answer 1

For many people,the best friend becomes a brother or a sister they'd always wanted.
对于很多人来说，最好的朋友成了他们一直想要有的一个哥哥/弟弟或一个姐姐/妹妹。

Answer 2

很多人都喜欢把最好的朋友当成自己的亲兄妹

Answer 3

答：对于很多人来说，他们都喜欢把自己最好的朋友当成亲兄弟看待。