please help me to find the mistakes

please help me to find the mistakes
yesterday, an interesting thing happened in our class.we was having  a biology class.the teacher brought us a  model of human skeleton.we were interested in it and talked with each other . the teacher asked us to stop talking ,but a naughty girl was still talking .the teacher asked her again then she stopped.after a while.someone laughed suddenly .it was a student who sat behind that talking girl.the student lauhged because the talking girl  pasted two paper tapes on her mouth and turned to the student. she looked very funnywe all looked over there,more and more students laugherd but the teacher did not do something.he teached us straight'human skeleton is very strange'the teacher said,'and human action is very strange too ,such as someone likes to paste something on the one's own mouth'we laughed at that girl the girl laughed too ,she had took off the paper tapes.  the teacher is very clver,isn't he?he didn't hit ther naughty girl and didn't scolded her but he let her not  do anything to disturb  discipline ,and  the girl wasn't embarrassed