Answer:
I know a word of letters three. Add two and fewer there will be. What is the word?
I am commonly abbreviated to H
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 jump when I walk and sit when I stand.
Though I am only two words I have thousands of letters in me
What is full of holes but still holds water
What am I?
Animal
Difficult
Easy
Food
Funny
Kids
Logic