In a young man worked hard and work hard; in middle age, when a down-man, cautious and conscientious work.

人在年轻的时候发奋图强，埋头苦干；在中年的时候踏踏实实做人，兢兢业业做事。

youdao

My roommate was interested in a young man in her English-literature class, but she was too shy to let him know.

我的室友对她英国文学课上的一个年轻人有意思，但又不好意思让他知道。

youdao

Her husband was assailed by a young man with a knife in a nearby park.

她丈夫在附近的公园遭到一个持刀青年男子的攻击。

《柯林斯英汉双解大词典》

But the deputy prime minister said al-Qaida first recruited the young man in Britain when he was a student in London.

VOA: special.2010.01.09

Greek novels usually were about a man and a woman, young,rich,who see each other and fall madly in love and passionately want one another.

希腊小说通常是关于男人与女人，年轻，富有，一见钟情,渴望对方。

耶鲁公开课 - 新约课程节选

Milton had written in Areopagitica that he had actually met Galileo on his journey, when Milton was a young man and Galileo was a very old man, through the continent.

弥尔顿在中已经写到,他实际上在旅途中曾经遇到过伽利略，那还是当他是一个年轻人，而伽利略已然老去的，一次环陆旅行中。

耶鲁公开课 - 弥尔顿课程节选

He told me that he had taken in a young man, Daniel Montalvo, who had recently blown.

NEWYORKER: The Apostate

But Zak also ran a study where he measured the oxytocin release in a young man who was communicating with his girlfriend via Facebook.

FORBES: Why We Need to Meet in Person

The sheik's morning began when two of his fighters brought in a young man they had stopped at a checkpoint with seven jerry cans of gasoline in his car.

WSJ: Kidnapping, Spats on Docket of Syria Rebel Boss