sober ·adjective (SERIOUS)
Definition: Someone who is sober is serious and thinks a lot. Level: C2
听到那个消息后，他整个晚上都情绪严肃。
After the news, he was in a ___sober mood all evening.
那次事件后，她通常开朗的性格让位于一种更为严肃的人生观。
Her usually cheerful nature gave way to a more ___sober outlook after the incident.
这位哲学家对人性的严肃分析与那位诗人的浪漫主义形成了鲜明对比。
The philosopher's ___sober analysis of human nature contrasted with the poet's romanticism.