The aim of students who came to school is to study. But to study requires (需要) a right way, or you waste either the time or the money. The following are the ways of studying.
   The best time for reading is morning, because in the morning, the air is fresh and the mind is clear. For that reason, we can get good result.
   In studying we must have patience (耐心). If we have not known a text well, we must read it again. We should not read the next one till we have learned the first one.
   When we are studying, we must put our hearts into the book, or we can get nothing from the book while we are reading.
   We must always ask “whys”. If it is not well understood, write it down and ask our teachers or our parents, or friends. In any possible way, we must know it completely and what we've learned can be used well and made better.
   Though there are many ways for studying, yet the above mentioned will be quite enough if we can keep them in heart and do so.

商鞅变法中推行下图所示标准器具的主要目的是？

采用燃烧法除去空气中的氧气，且不能混入新的气体，最好采用的可燃物是（ ）

（Ⅰ）令 $t=\frac{1}{2}\sin \left(\frac{\pi }{32}x\right)$ ，x∈0，24，求t的取值范围；

（Ⅱ）求函数M（a）；

（Ⅲ）为加强对环境污染的整治，市政府规定每天的综合环境污染指数不得超过2，试问目前市中心的综合污染指数是多少？是否超标？