真管真严 genuine management and discipline

严格认真的 scrupulous

严肃认真的 Ernest ; sober

非常严肃、认真 dead serious

严谨认真 Rigorous and precise ; He is a thorough scoundrel

严肃的、认真的 Deep ; serious

认真、严肃 serious about

庄严的极认真 solemn

认真严谨 Seriously stringent ; seriously

严肃认真 earnest and serious ; for real