请阅读短文。 AnneWhitney,asophomoreatColoradoStateUniversity,firsthadaproblemtakingtestswhenshebegancollege."Iwasalwayswellpreparedformytests.SometimesIstudiedforweeksbeforeatest.YetIwouldgointotakethetest,onlytofindIcouldnotanswerthequestionscorrectly.Iwouldblankoutbecauseofnervousnessandfear.Icouldn'tthinkoftheanswer.MylowgradesonthetestsdidnotshowwhatIknewtotheteacher."Anotherstudentinbiologyhadsimilarexperiences.Hesaid,"Myfirstchemistrytestwasverydifficult.Then,onthesecondtest,Isatdowntotakeit,andIwassonervousthatIwasshaking.Myhandsweremovingupanddownsoquicklythatitwashardtoholdmypencil.IknewthematerialandIknewtheanswers.YetIcouldn'tevenwritethemdown!" Thesetwoyoungstudentswereexperiencingsomethingcalledtestanxiety.Becauseastudentworriesandisuneasyaboutatest,hisorherminddoesnotworkaswellasitusuallydoes.Thestudentcannotwriteorthinkclearlybecauseoftheextremetensionandnervousness.Althoughpoorgradesareoftenaresultofpoorstudyhabits,sometimestestanxietycausesthelowgrades.Recently,testanxietyhasbeenrecognizedasarealproblem,notjustanexcuseorafalseexplanationoflazystudents. Specialuniversityadvisingcoursestrytohelpstudents.Inthesecourses,advisorstrytohelpstudentsbyteachingthemhowtomanagetestanxiety.Atsomeuniversities,studentstaketeststomeasuretheiranxiety.Ifthetestsshowtheiranxietyishigh,thestudentscantakeshortcoursestohelpthemdealwiththeirtensions.Thesecoursesteachstudentshowtorelaxtheirbodies.Studentsaretrainedtobecomecalminverytensesituations.Bycontrollingtheirnervousness,theycanlettheirmindsworkatease.Learnedinformationthencomesoutwithoutdifficultyonatest. AnexpertattheUniversityofCaliforniaexplains:"Withalmostallstudents,relaxationandlessstressarefeltaftertakingourprogram.Mostofthemexperiencebettercontrolduringtheirtests.Almostallhavesomeimprovement.Withsome,theimprovementisverygreat." Poorgradesareusuallytheresultof__________. 查看材料
A.poor sleeping habit
B.laziness
C.lack of sleep
D.inability to form good study habits
正确答案是D