Thisisanimportantproblem_______toofewsocialscientistshaveresearched.
A、whichD
into which 引導的是 problem 的定語從句。 which 指代 problem ，into 與 research 搭配。
Children have a natural ________ about the world around them.
It is not decided ________ the conference will be held.
ThedivisionofEnglishintoOldEnglish,MiddleEnglish,andModernEnglishisnonconventionalandnotarbitrary.
Thereisadeadlock(僵局)inthediscussionwhenneithersidegives________totheother.
______movesonascaleofthenationallanguage,dialects,andindividualwaysofcommunication.
