Answer:
I am full of holes but still holds water.
Always in you, sometimes on you. If I surround you, I can kill you. What am I?
I am an object which is used in baseball during the day I can't be seen at all
What loses its head in the morning but gets it back at night?
Flat as a leaf, round as a ring; have two eyes, can't see a thing. What am I?
Why did Superman flush the toilet?