Can you start the fire using two pieces of wood?

Which organisation is a specialized agency of the UN that deals with global health issues?

a) World Trade Organization (WTO)
b) World Health Organization (WHO)
c) International Monetary Fund (IMF)
d) United Nations Educational, Scientific and Cultural Organization (UNESCO)

Once upon a time, there was a castle on a square island. The entire island was surrounded by a 14m wide trench. The Romans had wanted to invade the castle and had brought a few wooden planks along with them to facilitate themselves in crossing the moat. The planks were however found to be only 13m long.

The Romans still managed to cross the trench. How did they do it?

The more of this there is, the less you see. What is it?

He loves to dance, twist and prance, he shakes his tail, and as a way he sails, wingless he flies into the sky. What is he?

If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?

Who always enjoys poor health?

Can you find a five letter word that is left with only two letters if one is removed?

I am eight letters long - "12345678"
My 1234 is an atmospheric condition.
My 34567 supports a plant.
My 4567 is too appropriate.
My 45 is a friendly thank-you.
My 678 is a man's name.

What word am I?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?