What Am I Riddles

Question: I take what you receive and surrender it all by waving my flag.What am I?

Question: Under pressure is the only way I work,
and by myself is the only way I'm hurt.

What am I?

Question: Thousands of orphans who lost their old home,
found by others who have lost their own.
To hide a secret that is obvious to all,
becomes even more obvious when the host falls.

What am I?

Question: What demands an answer, but asks no question?

Question: What is something that you always have with you but you always leave behind?