There are something different when I come back here.I found sentences like \" 节电妙招:在寝室及教室时请随手关掉不用的灯,白天尽量利用自然光\" are at end of every page.It\'s a very excellent idea to do this .I think everybody shoud apply these suggestions into everyday behaviors so that we can build a clean and healthy environment which is useful to everyone!![s:9]