As a teenager I was self-harming regularly.

我十几岁时经常自残。

《牛津词典》

I guess I had watched too many movies as a teenager.

我想我十几岁的时候看了太多的电影。

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Gradually, as I was a teenager, my hair color changed.

渐渐地，当我还是个青少年时，我的头发颜色变了。

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And the question is, as when one might read a paper one wrote six months ago or ten years ago when one was a college student, or a poem one wrote as a teenager, and looked at it and think: "Ha! Is it possible that I could have written that?".

同时，一个人可能重新阅读,六个月前，或者十年前,还是大学生时写的论文，或者青年时写的一首诗，然后问自己：,哈，这个东西是我写的么？

普林斯顿公开课 - 人性课程节选

And gradually as I was a teenager, my hair color changed.

等我成长后，我的发色开始发生变化。

I used to实战 - SpeakingMax英语口语达人

As a teenager I developed a great interest in not only horse breeding but also horse racing and used to bet based on red-hot tips.

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As a child I had spent my evenings at home doing schoolwork, or trying to get a picture on the black and white TV, as a teenager I'd lain in my room fiddling with my yellow transistor radio, waiting for my favourite tunes.

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When I was a teenager, as soon as I was able, I rushed down to our local library to register to vote.

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