並前往https://zh.khanacademy.org/math/zh-grade-1/x5448e77ecc4e60dc:zh-v2-100-yi-nei-shu-de-ren-shi-ji-jia-jian-fa-yi/x5448e77ecc4e60dc:zh-v2-bi-daxiao/v/greater-than-and-less-than-symbols