How do you say "I have been doing this for many years" in Chinese

Question

Answer

I 我
have been doing 从事
this 这项工作 （work or interests ？）
for many years 许多年了 
我从事这项工作许多年了or 许多年以来我一直从事这份工作。
But in Chinese，we ofen speak the time first in the sentence.

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我做这个已经做了很多年了。

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我做这个已经很多年了。It's depend on what 'this' means.If it means a job,我做这行已经很多年了。

Answer

多年来，我一直在做这个。