He was a young fellow, very green, very immature.

他是个年轻的家伙，没什么经验，很不成熟。

《柯林斯英汉双解大词典》

This is An An, a young fellow.

这位呢叫安安，是个小伙子。

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A young fellow that age tied to a woman of forty-five.

大好年纪的小伙束缚到一个四十五岁的女人身边。

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No matter how I look at this issue, I cannot escape being troubled by the fact that we have in place a policy which forces young men and women to lie about who they are in order to defend their fellow citizens."

VOA: special.2010.02.06

Vince's insurance gave him the freedom to take Zoe for a second opinion to Johns Hopkins' Sidney Kimmel Cancer Center in Baltimore, where she was assigned to Patrick Grohar, a young pediatric oncology fellow.

FORBES: Two Girls Two Countries One Cancer