Asweallknow,timeismoreimportant【建议改成valuable】thanmoney.Wewilltakepartin【theentranceexaminationtoseniorhighschool建议改成collegeentranceexamination】nextyear.Sowemustconcentrateonstudynow.

　　However,someofthestudentarealwayswastingtime.Theyoftenspend【more没有对比,你还是给成many吧】timeplayingcomputergames,watchingTVorsurfingtheInternet.Whattheydo【mustbe是对现在的推测,此处不妥】【badfor这种搭配过于枯燥建议改成】theirstudy.【整句建议Whattheydotendstobeunfavorabletotheirstudy】

　　SO【改Therefore吧】Ithink【别老用这种表达,改asfarasIcansee】wemustmakegooduseof【建议改个表达takefulladvantageof】ourtime.First【建议改firstandforemost不过你后面又没有second之类的,要有逻辑性】,wearesupposedtolistentotheteacherscarefully【inclass】.Then,afterclass,weshould【tryourbestto可省略】exercisemoretomakeusenergetic.【Then,afterclass别自己乱断句】Ifwedon'twastetime,wemust【will...】get【become】betterandbetter.I'msurewecanmakeit!【it是什么?自己知道阅卷老师知道吗?】