他那饱经风霜的多皱的脸上发着光彩，使人产生一种乐观的感觉。

There was a glow on his face, wrinkled by a life time of suffering, that inspired one with a feeling of unshakable optimism.

《新英汉大辞典》

随着最近文化主题电视节目的增长，一些人乐观的认为，这将有助于整个国家再次热爱文学。

With the recent boom of culture-themed TV shows, some are optimistic that this will help the country love literature again in general.

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当组织在扩张和增加人员时，晋升机会、加薪，以及与一个充满活力的组织联系在一起的兴奋感，会让人产生乐观的情绪。

When organisations are expanding and adding personnel, promotional opportunities, pay rises, and the excitement of being associated with a dynamic organisation create feelings of optimism.

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Here you have somebody who's happy, at ease, and completely secure that there will be food around the corner.

右边的人轻松乐观,百分百确信面包总会有的

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

I try to look on the bright side. I try to not be a downer.

我试着乐观一点。试着不去做一个扫兴的人。

幸福的定义 - SpeakingMax英语口语达人

Optimistic people, and again, not Pollyannaish detached optimism, but grounded optimists, on average, live significantly longer.

乐观的人，不是指盲目的乐天派，而是脚踏实地的乐观主义者，平均而言，明显更加长寿。

哈佛公开课 - 幸福课课程节选