Good Riddles

Question: We are 5 little items, and you can find us all in a tennis court.

Question: I never was. Am always to be. No one ever saw me, nor ever will. And yet I am the confidence of all who live and breathe. What am I ?

Question: "The Captain is my brother," testified the soldier. But the Captain testified he didn't have a brother. Who is telling the truth?

Question: What do you call a fly without wings?

Question: What goes up and never comes down?