说明：  这是一款帮助学生背单词的小软件。建立单词库，可从单词库中随机抽取单词，并随机隐去该单词中的一些字母，在屏幕上显示带空格的单词，用户对空格处的字母进行补全，程序判断填补是否正确，并统计正确率。 编程任务： 建立单词库，并可以方便地对单词库进行增加、删除。 随机读取一个单词。 随机隐去单词中的一些字母，规则是：长度为2～4空一个字母，5～7空二个字母，8～10空三个字母，11以上空四个字母。用随机数方式确定隐去哪几个位上的字母，并在屏幕上显示带空格单词。 用户填充空格处的字母，程序判断填充是否正确。 当用户结束游戏时，统计正确率，并输出相应的鼓励语句。
(This is a help students memorizing words software. The establishment of the word library, words, randomly selected from the word library, and omitted some of the letters of the word random word with a space displayed on the screen, the user complement the letters of the space, to fill the program to determine whether correct and statistical accuracy. Programming tasks: the establishment of the word library, and can easily be the word library for addition, delete. Random read a word. Randomly omitted some of the letters in the word, the rules are: length of 2 to 4 empty letter, 5-7 empty two letters, 8 to 10 empty three letters, four letters of 11 or more empty. Random number of hidden where few letters, and displayed on the screen with a space word. Users to fill in the letters of the space program to determine fill correctly. When the user ends the game, the statistical accuracy rate, and outputs a corresponding incentive statement.)