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 lose my head in the morning and regain back it at night.
I sit high glowing and watch the world go by. Without me everything would seem dull and dangerous. What am I?
I have branches but no fruit trunk or leaves. What am I?
Two bodies have I, though both joined in one. The more I stand still the faster I run. What am I?
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.