to be useful to the worldのすみからすみまで徹底研究します。
To Be Useful to the World Women in Revolutionary America, 1740-1790【電子書籍】[ Joan R. Gundersen ]
The Well at the World's End "Have nothing in your house that your house that you do not know to be useful, or to be beautiful."【電子書籍】[ William Morris ]
