Thereisadeadlock(僵局)inthediscussionwhenneithersidegives________totheother.

ThedivisionofEnglishintoOldEnglish,MiddleEnglish,andModernEnglishisnonconventionalandnotarbitrary.

Accordingtothe"principles-and-parameters"theory,"principles"refertohighlyabstractpropertiesofgrammarwhichareappliedtolanguageingeneralandwhichgeneratephrasesandatthesametimerestrainthepowerofMovea,while"parameters"allowgeneralprinciplestooperateincertainrestrictedways,accordingtowhichparticulargrammarsofnaturallanguagesvary.

Thisisanimportantproblem_______toofewsocialscientistshaveresearched.

Searle'sclassificationofillocutionaryactsisbasedontheclassificationofperformativeverbs.