sibling|siblings

我的兄弟姐妹和我关系密切。

My ___sibling and I share a close bond.

我有三个兄弟姐妹。

I have three ___siblings.

我也很幸运有一个兄弟姐妹，一个姐姐，她在我小时候照顾我。

I am also lucky to have a ___sibling, an older sister, who took great care of me when we were children.