Good Riddles

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?

Question: Three men were told by God, " If you step on a duck, you shall marry the ugliest woman. However, if you do not step on a duck, you shall marry the most beautiful woman in all the land." The three men accepted. The first man stepped on a duck from not paying attention. The second man accidentally stepped on a duck in his son's room. The third man never stepped on a duck and was then married to the most beautiful woman he's ever seen. But why was he really married to the beautiful woman?

Question: Two men/women in absolutely identical conditions have two of the exact same water bottles (full of water). An hour passes, and the temperatures of the water inside the bottles are measured. The temperature of one of the bottles is noticeably higher than the temperature of the other. Assuming that the temperature of the setting they were in, as they were both the same, had to do with the change in temperature of the water, why are they different?