"a sad expression" "a look of triumph" "an angry face"
"tears are an expression of grief" "the pulse is a reflection of the heart's condition"
"expressions of good will" "he helped me find verbal expression for my ideas" "the idea was immediate but the verbalism took hours"
"pardon the expression"
"he suggested a better formulation" "his manner of expression showed how much he cared"
"I concluded from his awkward constructions that he was a foreigner"
"the expression of milk from her breast"
误 When the name was mentioned, there was an expression in her face which I could not read.
正 When the name was mentioned, there was an expression on her face which I could not read.
析 “表情”是表面的,故说“脸上的表情”时,介词用on不用in。