Answer:
I am a protector. I sit on a bridge. One person can see right through me while others wonder what I hide.
They come out at night without being called. They are lost in the day without being stolen. What are they?
cloud is my mother wind is my father.
I come without being fetched at night, hide away as soon as daylight strikes. Although I may look small, I am much mightier than what you can imagine. What am I?
I am in the past, never in the future. I don't exist, but have existed. I saw what you saw, and this is what I will ever see. What am I?
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.