Good Riddles

Question: What can you hear but not see?

Question: No matter how hard you try,
I can open what you can't.
If it wasn't for me,
on your front porch you would stand.

What am I?

Question: I am a cave full of bones,
and the house of a worm.

What am I?

Question: A man challenges the greatest chess player in the world to two games of chess. He guarantees that he will win or tie at least one of the games for sure. To be even more cocky, the man says he will play both games at the same time.

How does he guarantee he wins or ties at least one game?

Question: 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 black babies. What Am I?