单选题Some students are so&nbsp

问题补充：

单选题Somestudentsareso______thattheyoftenmakemistakesintheirhomework.A.carfulB.seriousC.carelessD.successful

答案：

C解析词义辨析。careful仔细的；serious严重的；careless 粗心的；successful成功的。根据句意：他们做作业经常犯错误，应该是粗心才会引起错误的。故选C。