Black mud, White stone, Reflective water' is a pithy phrase for distinguishing obstacles of mountain roads on night hikes. Black for the mud, white for the stone and the reflective water for the little ponds on the ground.
'Even though the appearance of objects cannot be seen under night sky, the nature of them never change.'
(The text is provided by the student)「黑泥白石反光水」為夜行時辨別山路障礙物所記起的一句口訣，意指黑為泥，白為石，反光的表面則為小水坑。
