Tom never studied hard as a result he failed in mo

问题补充：

Tom never studied hard,as a result,he failed in most exams,which he------(填空a,thought little ofB,sang high praise forC,spoken highly ofD,was well spoken

答案：

A think little of sth 不重视某事

句中which引导非限制性定语从句,指代前面整句的内容