单选题 The professor can hardly find sufficient grounds ______ his argument in favour of the new theory.
A. for which to base B. on which to base
C. which to be based on D. which to base on

【正确答案】 B

【答案解析】[解析] to base sth．on sth．else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)。