The adverb 之一
The adverb 之一 
is used to single out one part of a whole. It is placed after a noun.
is used to single out one part of a whole. It is placed after a noun.Scheme
subject
predicate
object
之一
Examples
她是我的好朋友之一
She is one of my good friends
tā shì wǒ de hǎo péngyou zhīyī
这部手稿只是他们的珍藏之一
This manuscript is only one of their treasures
zhè bù shǒugǎo zhǐshì tāmen de zhēncáng zhīyī
它是世界上的贫穷国家之一
It is one of the poorest countries in the world
tā shì shìjiè shàng de pínqióng guójiā zhīyī
之一 is often used with the adverb 最 to form the construction "one of the most...".
to form the construction "one of the most...".Scheme
最
what
之一
Examples
纽约是世界上最国际化的城市之一
New York is one of the most cosmopolitan cities in the world
niǔyuē shì shìjiè shàng zuì guójìhuà de chéngshì zhīyī
成龙是最有名的中国明星之一
Jackie Chan is one of the most famous Chinese actors
chénglóng shì zuì yǒumíng de zhōngguó míngxīng zhīyī