他是四个孩子中最年长的。

He was ___the ___eldest of four kids.

她是最年长的——98岁——并且知道我们镇的整个历史。

She's ___the ___eldest - 98 years old - and knows the whole history of our town.

作为最年长的，她经常照顾她的弟弟妹妹。

As ___the ___eldest, she often takes care of her younger siblings.