1. 输入字符串sV后，将其中的标点符号（, . ! ?）转换成空格 。全部字符转换为小写字母； 2. 字符级检测：全部字符为小写字母、数字或空格； 3. 再次创建Scanner对象，从sV中扫描词组，= new Scanner(sV) ，用next()方法，将词组存放到字符串数组sVa[]中； 4. 词组级检测：剔除纯英文字符串以外的非法字符串； 5. 排序，剔除相同的英文单词，输出。

测试文本： The USB 3.0 specification was published on 12 November 2008. Its main goals were to increase the data transfer rate ,up to 5 Gbs, decrease power consumption, increase power output, and be backwards compatible with USB 2.0. USB 3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB 2.0 bus.For this reason, the new version is also called SuperSpeed.The first USB 3.0 equipped devices were presented in January 2010. -1. input string sV, which will be punctuation (.!?) Into space. All characters are converted to lowercase　2. character-level detection: all characters to lowercase letters, numbers or spaces　3. Create a Scanner object again,　sV scanning phrase, = new Scanner (sV), with the next () method, phrase stored in a string array sVa []　the level detector 4. phrase: exclude other than plain English string of illegal string　5. sorting, culling the same English words, output.

Test text:. The USB 3.0 specification was published on 12 November 2008. Its main goals were to increase the data transfer rate, up to 5 Gbs, decrease power consumption, increase power output, and be backwards compatible with USB 2.0 USB 3.0 includes a new, higher speed bus called SuperSpeed in parallel with the USB 2.0 bus.For this reason, the new version is also called SuperSpeed.The first USB 3.0 equipped devices were presented in January 2010.