This loop will create 26 documents, one for each lowercase letter of the alphabet, each document containing the character itself and its ASCII character code.
此循环将创建26个文档，代表字母表的每个小写字母，每个文档包含字符本身及其ASCII字符码。
2
These mutations - where oneletter of the DNA code is substituted for another - are a first step in evolution.
这些变异(即：DNA的代码中一个字母被另一个取代)是进化中的第一步。
3
Write their full names, three-lettercode and onelettercode.