题目内容：

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。

增加:在缺词处加一个符号(^),并在下面写出该加的词。

删除:把多余的词用斜线( \)划掉。

修改:在错的词下划一横线，并在该词下面写出修改后的词。

注意: 1. 每处错误及其修改均仅限一词;

2.只允许修改10处，多者(从第11处起)不计分。

Keeping hands clean is one of the most basic ways of prevent illness. Yesterday, I teach my three-year-old sister how to wash hands proper. Firstly, I asked her to wet her hand under running water and apply soap to them. Before, she rubbed hands well with soap for at least twenty seconds, I told to her to wash off all of the soap. Lastly, I gave him a clean towel to dry her hands. She very glad and showed me her clean hands. Looked at her smiling face, I felt such happy that I gave her a new storybook.