The surface of the rock expands very slightly, but the inside of the rock, which is not heated, does not expand. This causes a little crack, and gradually little pieces of the rock break away.

• 岩石的表面膨胀很小，但是没有被加热的岩石的内部却不膨胀，这使得岩石产生细小裂缝，一片片小石头片将渐渐地剥蚀下来。