2、dertheSupervisionofZhangSijieJune10,2016IVIVAcknowledgementsIn the process of the writing of this paper,myteacherZhangSijiedevoted a greatdeal ofeffortstomythesis, fromchoosingthetopictothethesisproposal,fromtheoutlinetothewholethesis,hepointed out thespecificissues in themov
3、erandoveragain, strictlyand persuasively. I express my sincerelythankstohim. Meanwhile, I would also like to thankmy teachers,classmatesandfriends, I was given great care and support inthetimeoffinishmythesis.Writingathesisisasystematiclearningprocess.Thecompletionofthethesis