Introduction Our wants seem to be never-ending, when one want is satisfied another one will emerge immediately.So it's very important for the producers and the dealers to make clear what people want and understand the trend of wants,for only in this way can they insure their goods are saleable. 刿价爱有質易大孝Introduction Introduction Our wants seem to be never Our wants seem to be never -ending ， when one want is satisfied , another one when one want is satisfied , another one will emerge immediately. So it will emerge immediately. So it ’s very important for the producers and the important for the producers and the dealers to make clear what people want dealers to make clear what people want and understand the trend of wants, for and understand the trend of wants, for only in this way can they insure their only in this way can they insure their goods are saleable. goods are saleable