北京市加大高新技术产生的发展，有利于

下列物质中属于混合物的是 ____（填序号，下同），属于化合物的是 ____，属于单质的是 ____。

①空气 ②金刚石 ③高锰酸钾 ④水银

     There are two days we shouldn't worry about in our life. One is yesterday,____  Yesterday is gone forever.____ So it is useless to worry about it.  We cannot control tomorrow.____ maybe something good or bad. No matter tomorrow is sunny or cloudy, the sun will rise as usual.  So we have only one day left. What is it?____Today is the most important for everyone. It is the only day for us to fight for ourselves. We can control it. We can choose what to do and what not to do. We can choose how to do it. Treasure Today,____