多年

他已消失多年了。

tā yǐ xiāo shī duō nián le.

It's been years since he disappeared.

她背痛了好多年了。

tā bèi tòng le hǎo duō nián le.

She's been having trouble with back pain for years.

我父亲经营外贸多年。

wǒ fù qīn jīng yíng wài mào duō nián.

My father has been engaged in foreign trade for many years.