Question

Some students are so ______ that they often make mistakes in their homework.

A．carful

B．serious

C．careless

D．successful

Answer 1

C

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。