----Must I do well in all the subjects Mum?----Sure baby! As an old saying goes knowled

问题补充：

----Must I do well in all the subjects, Mum?

----Sure, baby! As an old saying goes, knowledge is .

A. command

B. effort

C. power

D. energy

答案：

A. command

B. effort

(答案→)C. power

D. energy

解析：词义辨析。A要求，命令；B努力；C权利，力量；D能量，精力；句意：—妈妈我非在所有学科中都表现很好吗？—当然。正如谚语所说：只是就是力量。根据句意说明C正确。