In a competitive economy, the consumer usually has the choice of several different brands of the same product．Yet underneath their labels, the products are often nearly identical．Thus, manufacturers are confronted with a problem how to keep sales high enough to stay in business．Manufacturers solve this problem by advertising．They try to attract consumers in various ways．As a matter of fact, advertisements may be classified into three types according to the kind of appeals they use.
One type of advertisement tries to appeal to the consumer's reasoning mind．It may offer a claim that seems scientific．For example, it may say the dentists recommend Flash toothpaste．In selling a product, the truth of the advertising may be less important than the appearance of truth．A scientific approach gives the appearance of truth;
Another type of advertisement tries to amuse the potential buyer．Products that are essential boring, such as insecticide, are often advertised in an amusing way．One way of doing this is to make the products appear alive．Advertisers believe that consumers are likely to remember and buy products that the consumers associate with fun,
Associating the product with something pleasant is the technique of the third type of appeal．In this class, ads suggest that the product will satisfy some basic human desire．One such desire is the wish to be admired by other people．Many automobile advertisements are in this category．Another powerful desire to which advertisers appeal is the desire for love．Thus ads for bandages(绷带) are unlikely to emphasize the way the bandages are made or their low cost; instead, the ads may Show a mother tenderly binding up and then kissing her small boy's cut finger．In the picture there is an open package of Ouch Bandages．The advertiser hopes the consumer will mentally insert an equal sign to create the equation 'Ouch Bandages=Love'.
One only needs to look through a magazine or watch an hour of TV in order to see examples of these three different advertising strategies.
Under the cover of different brands,______.