應該很難 因為你看不到

http://s850284.pixnet.net/blog/post/45490468-tepe-%E7%89%99%E8%8F%8C%E6%96%91%E9%A1%AF%E7%A4%BA%E5%8A%91(%E7%A2%87)-(%E5%A4%9A%E5%8F%A3%E8%85%94%E7%85%A7)