2, the source is different: good night: from the "Adventures Seen in Twenty Years" the first time 103 "I only suffered my second grandmother, and I want to return him to the rules of being a daughter-in-law. I invite good morning, good afternoon and good night every day. " An An: Ya Di Yi, a poem from China's first collection of ancient poems, The Book of Songs. "Holding the news again and again, you are safe." Catch prisoners in droves and cut off the enemy's ears calmly and peacefully. )
3, the use of different scenarios: good night: generally used for evening greetings. An An: Generally used for young people, mostly for women.