Writing prompt: When I Have a Different Opinion

Student essay:
If you and your classmate have different opinion,what will you do?I often respect my classmate's opinion and find why our opinion are different.If I was wrong I would chenge my opinion until it was right.If my opinion was right I must do something to change everyone's opinion.
Why I want to do this.Because I know the right thing is only one.Though there have no pure water and no pure milk,we needed do something to make it pure.
I think one day the world will be better because of me.
So what is your opinion.

Corrected essay:
If you and your classmate have different opinions, what will you do? I often respect my classmate's opinion and find out why our opinions are different. If I am wrong, I will change my opinion until it is right. If my opinion is right, I must do something to change everyone's opinion.
Why do I want to do this? Because I know the right thing is only one. Though there is no pure water and no pure milk, we need to do something to make it pure.
I think one day the world will be better because of me.
So what is your opinion?