n.乐观主义,乐观 (opp. pessimism)。n.-ist cautious optimism: 审慎乐观choose optimism: 选择乐观coefficient of optimism: 乐观系数criterion of optimism: 乐观准则epistemological optimism: 乐观主义的认识论下载手机词典可随时随地查词查翻译