Уже несколько лет он работает над н

Уже несколько лет он работает над новым двигателем, и его единственное желание - завершить эту сложную работу

Results (English) 1:

For several years he worked on the new engine, and his only desire - to complete this complex work

Results (English) 2:

For several years he was working on a new engine, and his only desire-to finish this difficult work

Results (English) 3:

For several years now he is working on a new engine, and his only desire is to complete this complex work