Answer:
I am an instrument that you can hear but cannot see or touch. What am I?
There was a green house. Inside the green house there was a white house. Inside the white house there was a red house. Inside the red house there were lots of babies. What is it?
I am a protector. I sit on a bridge. One person can see right through me, while others wonder what I hide. What am I?
Poor people have it. Rich people need it. If you eat it you die. What is it?
I am an instrument capable of making numerous sound but cannot be touched or seen.
Why did Superman flush the toilet?