Twitterでみかけたおもしろ画像。 Texting & walking is such a big problem at this school that they had to reinvent their stairs! http://t.co/2O9JaWwm3I pic.twitter.com/iRxNNFK8Ti — Revision3 (@Revision3) 2015, 6月 19 スマートフォンを使いなが…