He changed the engine to improve the performance of the car.

My car needs to have its engine replaced.

The performance of this computer is very high.

The engine of this car is very powerful.

We are always aiming for the improvement of our services.

We are always aiming to improve our services.

She attended the party in her new outfit.

If you rephrase that complex theory in simpler terms, it's just common sense.

I exchanged dollars for yen.

He is my best friend.