假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处错误，每句中最多有两处，每处仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号（^），并在其下面写出该加的词。
删除：把多余的词用斜线（\）划掉。
注意：1．每处错误及其修改均仅限一词；
2．只允许修改10处，多者（从第11处起）不计分。
A survey basing on 1，000 students found that 80% of senior students sleep
less than nine hours every night．One main reason lies at students' bad habits．
Too much homework is given by school teachers is another main cause．Some students
are absent-minded while doing their homework，and some wasting their after-class time．
The third cause is that some students have to get up earlier on weekday to get toschool that was far away from home．Experts think an amount of homework for the students should be cut down．Beside，teachers should encourage their students makegood use of their spare time．Only in this way can the students improve our study efficiency．