Theprofessorcouldhardlyfindsuffientgrounds_______hisargumentsinfavorofthenewtheory.
A.tobebasedonB.tobaseonC.whichtobaseonD.onwhichtobase
为什么C选项不行?我咋觉得CD可以替换
回答时尽量详细
要解释另三个选项为啥不行
就这么多了.
thankyou~