Sure, here are the sentences with repeated comparatives:

1. It becomes harder and harder to find a job in big cities.
2. Your English is getting better and better.
3. These days more and more people are learning English.
4. That hole in your pullover is getting bigger and bigger.
5. My bag seemed to get heavier and heavier when I carry them.
6. As I waited for my interview, I got more and more nervous.