Smile when the phone. The caller will hear it in your voice.
A. taking up
B. putting up
C. picking up
D. bringing up
网友回答
A. taking up
B. putting up
(答案→)C. picking up
D. bringing up
解析：句意，当拿起电话时要微笑，打电话的人可以从你的声音中听出来。taking up占用 putting up张贴 picking up拿起 bringing up养育，根据题意，故选C。