Mary and Jane are both very quite but them their younger brother Tom is quite naughty.A.

问题补充：

Mary and Jane are both very quite, but them, their younger brother Tom is quite naughty.

A. like

B. alike

C. unlike

D. with

答案：

A. like

B. alike

(答案→)C. unlike

D. with

解析：：词义辨析。A像…一样；B形容词相似的；C不像…；D和，跟随，与…一致。句意：玛丽和Jane都非常安静，但是和她们不一样，她们年轻的兄弟Tom相当调皮。故C正确。