单选题 Jack is good, kind, hard-working and intelligent. ______, I can't speak too highly of him.
【正确答案】 C
【答案解析】(in a word总而言之)。句意为:杰克友好、善良、勤奋而又聪明。总之,我无论怎样赞扬他都不过分。A.as a result作为结果;C.by the way顺便说;D.on the contrary正相反。