Answer:
What do you get when you mix lemons with gun powder?
I'm really blue but when you see me I'm red. You don't see me too often. I'm there for you if you're hurt.
I pass before the sun, yet make no shadow. I'm all around you, but you cannot see me. What am I?
I help you carry your books.
I am black within and red without With four corners round about.
What language does a billboard speak?