Answer:
What do you throw out to use and take in when you're done?
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.
A man is pushing his car along the road when he comes to a hotel. He shouts, "I'm bankrupt!" Why?
A horrid monster hides from the day, with many legs and many eyes. With silver chains it catches prey. And eats it all before it dies. Yet in every cottage does it stay. And every castle beneath the sky.
It's in your hand though you can not feel it. Only you and time can reveal it.
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?