填空题：根据以下材料，回答题。The most obvious purpose of advertising is to inf

根据以下材料，回答题。
The most obvious purpose of advertising is to inform the consumer of available products or services. The second(31)__________ is to sell the product. The second purpose might be more important to the manufacturers than the(32) __________. The manufacturers go beyond only telling consumers about their products. They also try to per-suade customers to buy the (33) __________ by creating a desire (34)__________ it. Because of advertisement, con-sumers think that they want something that they do not need. After buying something, the purchaser cannot alwaysexplain why it was (35) __________.
Even (36)__________ the purchaser probably does not know why he or she bought something, the manufacturers(37) __________. Manufacturers have analyzed the business of (38)__________and buying. They know all the differ-ent motives that influence a consumer--s purchase--some rational and (39) __________ emotional. Furthermore, theytake advantage of this (40) __________.
Why (41)__________so many products displayed at the checkout counters in grocery stores? The store manage-ment has some good (42) __________. By the time the customer is (43) __________ to pay for a purchase, he or shehas already made rational, thought-out decisions (44) __________ what he or she needs and wants to buy. The(45)__________feels that he or she has done a good job of choosing the items. The shopper is especially vulnerableat this point. The (46) __________of candy, chewing gum, and magazines are very attractive. They persuade thepurchaser to buy something for emotional, not ( 47 ) __________ motives. For example, the customer neither needs norplans to buy candy, but while the customer is standing, waiting to pay money, he or she may suddenly decide to buy(48) __________ This is exactly (49)__________ the store and the manufacturer hope that the customer will(50) __________. The customer follows his or her plan.
第(31)__________。