zài / zhuān jiā / miàn qián / kuā kuā qí tán / què / ná bù chū / zhèng jù / nán miǎn / yí xiào dà fāng

在专家面前夸夸其谈却拿不出证据，难免贻笑大方。

Boasting in front of experts without being able to produce evidence is bound to make oneself a laughingstock.