a set expression [smile]
こわばった表情[笑顔]
a severe voice [look, expression]
険しい声[顔つき,表情]
a significant look
意味ありげな表情
a soft heart [side, expression]
優しい心[面,表情]
a solemn expression
まじめな表情
a sour smile [look]
不愉快そうな笑み[表情]
a stereotyped expression
型どおりの表情
a stern look [face]
けわしい表情
a stony look
無表情なまなざし
a swift current of information
情報の迅速な流れ