Answer:
I have cities but no houses I have mountains but no trees I have water but no fish. What am I?
What dress does everyone have, but no one wears?
When young, I am sweet in the sun. When middle-aged, I make you gay. When old, I am valued more than ever. What am I?
I march before armies, a thousand salute me. My fall can bring victory, but no one would shoot me. What am I?
I go inside boots and outside shoes.
No matter how little or how much you use me, you change me every month.