The range two (two) is the 2nd positive integer and the initial key range. It really is even, and is also the only real even key (the primes besides 2 are known as the odd primes). The range 2 is likewise equal to its factorial because . 知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。 https://samuelu011mta0.wikicorrespondent.com/user