Fresh air and fresh water build fresh mind,in my opinion.
Tonight,i went to classroom for learning,it is really hot in it.I wandered why any of them didn't chose to open the window and let fresh air come in, and how students were learing in such an enviroment which was severe lack of oxygen.
Then i opened a window.However,someone shut it down after a while.How could do such a stupid thing? We need oxygen.
At last, i finished my study,felt a little bit headache.
I'll never let it happen again.
