Sam some knowledge of the puter just by watching others working on it..
A. brought up
B. looked up
C. picked up
D. set up
网友回答
A. brought up
B. looked up
(答案→)C. picked up
D. set up
解析：考察动词短语辨析。A抚养，养育；B查找；抬头看；C捡起；用车接；无意中学会；接受信号；康复。恢复；染上…；D建立，成立；句意：Sam通过看别人玩电脑无意中学会了一些电脑方面的知识。根据句意说明本句使用pick up表示无意中学会。故C正确。