This behavior regards as impolite.

这种行为被视为无礼。

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Otherwise, it would be considered as impolite. This rule sounds simple, but is difficult to practice, especially for Chinese.

这条规则听起来挺简单，但对中国人来说实践起来却不是那么容易，尤其是吃面条。

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The Count acknowledged the two newcomers as briefly as was possible without being impolite.

伯爵尽可能简短而又不失礼节地向两位新来者打招呼。

《柯林斯英汉双解大词典》

Before, 'voicing their good fortune among higher- carbon colleagues was seen as impolite, ' said Paul Bledsoe, director of communications and strategy at the National Commission on Energy Policy, a bipartisan research organization.

FORBES: Commentary

In the Western world, too little eye contact is interpreted as being impolite, insincere, or even dishonest.

FORBES: The Impact of Eye Contact

In the US it can be seen as more than impolite to question religious-based beliefs.

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