此题要求改正所给短文中的错误。对标有题号的每一行做出判断：如无错误在该行右边横线上画一个勾(∨)；如有错误(每一行只有一个错误)，则按下列情况改正：
此行多一个词:把多余的词用斜线(＼)划掉，在该行右边横线上写出该词，并也用斜线(＼)划掉。
此行缺一个词：在缺词处加一个漏字符号(/\)，在该行右边横线上写出该加的词。
此行错一个词：在错的词下划一横线，在该行右边横线上写出改正后的词。
注意：原行没有错的不要改。
Dear fellow students,
Our school is aimed to build a “harmonious campus” .           
As a high school students, we should behave ourselves. But                               
some students are badly behaved. They threw rubbish about                             
and listen MP3 or sleep in class. A few boys even smoke and copy               
other students homework. I think it has a bad effect on their health as            
good as their study. A “harmonious campus” should have civilized              
students. So we should be strict on ourselves. Of course, study is the            
first. But we should study hardly. In order to build a harmonious                    
study atmosphere, they must develop good habits.       If everyone                   
makes a contribution to build our campus, I’m sure                               
our school will become beautiful and harmonious.                                   
Yours,
Li Qiang