单选题 The professor can hardly find sufficient grounds ______ his argument in favour of the new theory.
【正确答案】 B
【答案解析】[解析] to base sth. on sth. else意为“把……建立在……的基础上”,介词on在本题中提到了从句句首,which为关系代词,代替前面的先行词grounds“理由,根据”。