称准至0.0002克，就是称量一个物品时开启两次天平，两次结果之差不超过0.0002

(J: Jerry；S: Salesgirl(女售货员))
S: May I help you?
J: Yes,   1  
S: The dresses are over there.   2 
J: I like pink.
S: What about this one?
J: It looks nice.   3  
S: Sure. The changing room(更衣室) is over there.(After a moment)
J:   4  
S: You look very nice.
J:   5  
S: One hundred yuan.
J: One hundred yuan? Are you kidding? What about 80 yuan?
S: All right, 80 yuan.