Some scientists believe that birds do sing some of the time just because they are happy.

一些科学家认为鸟类是这样唱的时间仅仅是因为他们很高兴一些。

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Some scientists believe that birds do sing some of the time just because they are happy. However, they sing most of the time for a very different reason.

一些科学家相信，鸟类有时唱歌的确是因为自己很快乐。然而它们大多数时候是因为不同的原因而唱歌的。

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If they decide to invest in color-changing tile that looks like slate at first glance, because it makes them happy, then who are we to deny their choices?

如果他们决定投资第一眼看上去像是石板砖的变色瓷砖，因为这让他们高兴，那么我们凭什么去否定他们的选择呢？

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They thought everyone who'd be taking this class would be taking it because they are already really happy and they want to study about how amazing they are.

他们认为每个上这门课的人会上这门课,是因为他们已经很幸福了,他们想研究自己到底有多棒。

哈佛公开课 - 幸福课课程节选

The industry body points to research saying people do not switch banks very often because they are happy with the products and services they receive.

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Helping the musicians hear themselves and each other is the most important thing because if they are happy they are going to produce the best results.

FORBES: Connect

"Some of those people are not happy because they don't want to stay at Taiyuan, " the female worker said.

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