http://www.twword.com/uploads/wiki/95/a7/5451_7.jpg
楔形文字
http://www.newsancai.com/images/stories/newphoto/2010/News/World/20100905zz.jpg
阿拉伯數字
中國古代科技
https://www.google.com.tw/search?q=%E4%B8%AD%E5%9C%8B%E5%8F%A4%E4%BB%A3%E7%A7%91%E6%8A%80&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj1iJ_h6K7QAhUCj5QKHdRODXYQ_AUICCgB&biw=1476&bih=726
https://www.youtube.com/watch?v=rVlhMGQgDkY
