此题要求改正所给短文中的错误。对标题有题号的每一行作出判断：如无错误，在该行右边横线上画一个钩（√）；如有错误（每行只有一个错误），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：在错的词下面画一横线，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 my younger brother,
I’m writing to discuss the problem of bringing the         76. _________
mobile phone to school with you. I think that is            77. _________
very common of young people to have a mobile phone         78. _________
nowadays for it is very convenience. But                   79. _________
many students fail use it in a proper way, so it often      80. _________
interrupts the class and even affect their studies. As a        81. _________
middle school student, you don’t have to get in the touch     82. _________
with others during your school time. I hoped you can learn     83. _________
some useful lesson from others’ experience. You had better     84. _________
not bring my mobile phone with you when you go to school.      85. _________
Love,
Li Dong