Answer:
People see through me, but none pass through without killing me. I can be anywhere, and can be seen double or single. What am I?
I am needed for most animals and hardcover books. What am I?
I wear a green jacket on the outside white jacket as a second layer and red jacket inside. I am pregnant with a lot of babies. (one word)
What can travel around the world while staying in a corner?
What room do ghosts avoid?
If itβs information you seek, come and see me. If itβs pairs of letters you need, I have consecutively three. What am I?