[yòng xīn]
(集中注意力) diligently; attentively; with concentrated attention
do some hard thinking
用心去想一想
concentrate on one's studies; study diligently
用心学习
listen attentively to a lecture
用心听讲
work hard at exercises
用心做习题
have ulterior motives
别有用心
vicious intention
用心不良