when the snow falls,为什么是 falls 而非 fall 或者……?

when the snow falls,为什么是 falls 而非 fall 或者……? When snow falls,it comes down from the sky.为什么用falls , Let the sky fall.和When the sky falls.为什么fall一个不加s一个加s? When the three falls,the monkeys scatter. 求when the love falls 简谱! "when the night falls"的歌名是什么? "when the tree falls,the monkeys scatter"的意思 When the tree falls,the monkeys scatter什么意思 niagera falls 是哪里? park falls是哪 she falls ill.fall的第三人称是什么? fall down什么时候写成falls down