Answer:
Come up and let us go. Go down and here we stay
I have four wings but cannot fly. I never laugh and never cry. On the same spot always found, toiling away with little sound.
What do you fill with empty hands?
Slayer of regrets, old and new, sought by many, found by few.
What has two legs but doesn't walk?
Almost everyone needs it, asks for it, gives it. But almost nobody takes it.