Answer:
I am a certain five-letter word and become shorter when you add two letters to me. What am I?
I run through hills. I veer around mountains. I leap over rivers and crawl through the forests. Step out your door to find me. What am I?
I sleep when you are awake, I am awake when you fall asleep. I can fly but no feathers to aid my flight. What am I?
The more of me you take, the more I appear behind you. What am I?
you can throw me away but I will always be coming back
My days are numbered. What am I?