Missed opportunity

a, there are many entertainment facilities, billiards, singing, mahjong. In the south of thehall, there is also a stage, which is prepared for some big company parties. At this time, there is a piano... not been used for several years."Black Gold invitation!""it's a black gold invitation!""Mr. Lu hasn't used this kind of invitation for many years."this young man was able to get this invitation!the h...