办公室里那个爱显摆的家伙又在会议上发表了自作聪明的评论。

That ___smart-aleck in the office made another know-it-all comment during the meeting.

别在那自作聪明了，我们都知道你其实不清楚细节。

Stop acting like a ___smart-aleck—we all know you're not familiar with the details.