After several days of social activities, I decided to _ on my research on the human behaviors.
A. fix
B. settle
C. set
D. concentrate
网友回答
A. fix
B. settle
C. set
(答案→)D. concentrate
解析： 考查词义辨析。fix 安装，settle 定居，set 创立，concentrate 专注，句意：几天的社交活动之后，我决定全神贯注于关于人类行为的研究。所以选D。