单选题 Mark was intent on maintaining his status as first in his class, because even the smallest mistakes infuriated him, he reviewed all his papers _____ before submitting them to his teacher.无
【正确答案】 C
【答案解析】句意： 马克意在保持其班级第一的地位， 因为再小的问题也会激怒他， 每次上交作业前， 他都会刻苦地检查所有， 丝毫不差。 explicitly明确地； 明白地。 perfunctorily敷衍地； 潦草地。 mechanically机械地。 assiduously刻苦地； 勤勉地。 结合语境， C为最佳答案，故选C。