fAnswer: A new source of high quality denim fabric
Explanation:
A shift from PPF1 to PPF2 would suggest a new improvement due to technology, innovation or raw material. Here a new source of high quality fabric would result in more and better production of fabrics.
you could say something like your friends or your pets if you have any pets you could say something like you are grateful that we now have 3 vaccines for the Coronavirus or like you are grateful for your hobbies because it gives you something to do in your free time.
