From a broader perspective， price is the mechanism for allocating goods and services among potential purchasers and for ensuring competition among sellers in an open market economy. If there is an excess of demand over supply， prices are usually bid up by consumers. If there is an excess of supply over demand，__5__.
　　Exercise：
　　A a price contains a
　　ll the terms of purchase
　　B obtained by the purchase of a new bottling machine by a soda manufacturer
　　C where the consumer gives the seller money plus a trade-in
　　D available for other items
　　E prices are usually reduced by sellers
　　F price means what one pays for what he wants
　　key：BDACE