富士山，为什么那么对称？

Mount Fuji is a famous mountain in Japan. 富士山是日本有名的山。 It is a volcano, but now it sleeps. 它是座火山，现在却在睡觉。 Each eruption piled up more lava. 每次喷发都堆起更多岩浆。 The pile grew into a perfect cone. 堆着堆着，就成了匀称的锥形。 Its two sides look almost the same. 它两边看起来几乎一模一样。 It looks just like a work of art. 它看上去就像一件艺术品。