AcknowledgmentsFirst,Iwanttoexpressmysinceregratitudetoallthosewhohelpedmeduringthewritingofthethesis
MydeepestgratitudegoesfirstandforemosttoProfessorLiQiang,mysupervisor,forhisinstructiveadviceandusefulsuggestionsonmythesis
Withouthisconstantencouragementandguidance,Icouldnothavefinishedthesisonschedule
Iamdeeplygratefulofhishelpinthecompletionofthisthesis
Second,withtheprofoundknowledgeandwritingguidanceofteacher,Mr
LiQiang,Ihaveacquiredalotusefulthingsinthisclass
Meanwhile,Heledustodomuchpracticeinthewritingofthesis,andlearnedhowtowriteathesiswell
IalsooweaspecialdebtofgratitudetoalltheteachersandprofessorsinForeignLanguageInstitute,fromwhosedevotedteachingandenlighteninglecturesIhavebenefitedalotandacademicallypreparedforthethesis
Finally,Istillexpressmysinceregratitudetomyfriendsandm