十五年的用法和樣例：
例句
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我學英文已有十五年之久。
I have been learning English (for) as long as 15 years. -
我花十五年工夫才發覺自己沒有寫作的才能，但我無法放棄這一行，因為到了那時候我已經太出名了。
It took me fifteen years to discover I had no talent for writing, but I couldn't give it up because by that time I was too famous. -
她當了十五年的訟務律師之後，擔任了御用律師。
After fifteen years as a barrister, she took silk.
