Answer:
It's in your hand though you can not feel it. Only you and time can reveal it.
I can climb mountains, cross streams, handle hundreds of feet each day, yet I never move. What am I?
I am bought by the yard but worn by the foot
The last woman on Earth received a phone call. Who was the caller?
I have 24 keys but cannot open any locks. Sometimes loud, sometimes soft. What am I?
No matter how little or how much you use me, you change me every month.