文章（包括我填对的格子就一并打出来了）
Youshouldhavegoodstudyhabits.Thenyoucanspendlesstimebutlearnmore.
First,makefulluseofyourtime.Areyourbooksopen?Ifso,pleaseturnoffyourTVandputawayyoursnacks.Ofcourse,youneedsometimetoplay.Butyoushouldplayafterstudy.Remember:Studycomesfirst.
Second,listentoyourteacherscarefullyinyourclass.Youknow,itisveryimportant.Ifyouhavequestions,justaskyourteachers.Theyareverygladtohelpyou.
Third,doyourhomeworkbyyourself.Ifyoucan'tworkoutaproblemsuccessfully,youcanaskforhelp.Butyoucan'tjustcopy.Makesurethatyouu_______it.
Finally,takeanotewithyou.Sometimesyoumayhavesomeideasorquestions.Pleasewritethemdown.Thenyoucantalktoyourteachers,parentsorfriends.
Thesefourtipsarehelpfultoyou.Pleasehaveatry,myboy!Youwillsucceedifyouhavegoodstudyhabits.
画线的地方肯定是填understand没有问题,但是是用什么时态呢?我写的是过去式understood但有同学写的是原形,纠结了.
不是应该确保（说话时已经）懂了吗?
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