Sentences Corrections

Could anybody correct these sentences for me and explain those important mistakes that I make in the sentences below in detail?

These were the dialogues that I took down in the meeting of class decoration competition in my class.(They spokeChinese and then I translate into English)

great thanks in advance

Chairman:We don't want to draw wall picture with person.I think drawing picture which is relevant to science is better.Those bad and old habit shouldn't exist anymore.Being different from last year, We have only over thirty students this year .So we can't start working seriously at the eleven hour this year.Surely,our target is very simple, we want to get the first place.

Monitor:With you, we mustn't rank first.

Chairman:Basically, what we want to do is to destroy the statue. I don't require anyone to leave in the school after school everday.But if you leave after school, you must work very seriously. Sometimes, it's very difficult for us assign jobs to every one.So you should look for work by yourselves when you are free.