Sam some knowledge of the computer just by watching others working on it.A. brought up B.

问题补充：

Sam some knowledge of the computer just by watching others working on it.

A. brought up

B. looked up

C. picked up

D. set up

答案：

A. brought up

B. looked up

(答案→)C. picked up

D. set up

解析：考查短语辨析。brought up培养，提出，looked up查字典，picked up捡起，偶然学到，set up 建立，句意：山姆只凭看见别人从事电脑工作他就偶然学会了一些计算机知识。故选C。