Thisisanimportantproblem_______toofewsocialscientistshaveresearched.
A、whichD
into which 引导的是 problem 的定语从句。 which 指代 problem ，into 与 research 搭配。
Searle'sclassificationofillocutionaryactsisbasedontheclassificationofperformativeverbs.
Bloomfielddrewon______psychologywhentryingtodefinethemeaningoflinguisticforms.
Thebasicunitinthestudyofmorphologyis______.
He said that the group ________ him a letter and asked him to go there for an interview.
Thereisadeadlock(僵局)inthediscussionwhenneithersidegives________totheother.
