这个成语用来比喻讲话或写文章时，在关键地方加一两句重要的话，使内容更加生动有力。

　　Putting the Finishing Touch to the Picture of a Dragon

　　In the Southern and Northern Dynasties Period (420-589), there was a painter called Zhang Zengyou. Once he visited a temple and painted on the wall four dragons, but gave none of them eyes. The onlookers felt that was odd, and asked why he hadnt painted the eyes. He answered:"Eyes are crucial for dragons. with the eyes painted on, the dragons would fly away." Nobody believed this,so Zhang Zengyou took up his brush and added eyes to two of the dragons. No sooner had he finished than the two dragons flew into the sky amid a thunderstorm. The two without eyes stayed painted on the wall.

　　This idiom is used to describe how, when writing or speaking, one or two key sentences will enhance the contents.

本文来自：逍遥右脑记忆 http://www.jiyifa.com/youer/327425.html

相关阅读：