解开衬衫纽扣，让我听听的肺。

Unbutton your shirt and let me listen to your lungs.

youdao

他的衬衫少了3颗纽扣。

Three buttons were missing from his shirt.

《柯林斯英汉双解大词典》

他的衬衫上掉了一颗纽扣。

A button was missing from his shirt.

youdao

Or I have once been to a party and I found my shirt was misaligned, seriously misaligned, not one button but--Anyway, so--and so I feel when this happens I'm very immature.

或者有一次我去参加聚会,我发现我的衬衫扣错了，扣得很错，不只是扣错一粒纽扣，发生这种事时，我觉得太没面子了。

耶鲁公开课 - 心理学导论课程节选