A、The mail. B、The poster. C、The text D、The magazine. A四个选项都是不同形式的媒体，推测本题与某种媒体的特点有关。听音时应注意各个媒体的具体信息。讲座提到，最广泛使用的广告媒体是直接媒体，而信件是最普遍的

In a modern society, no company can hope to make a profit on any product unless it advertises it first [16] The most important decision that a company has to make regarding advertising is where to advertise. On TV? In magazines? On the radio? In newspapers? We refer to these means of communication as "the media". [17] There are three categories of media: print, broadcast, and direct. Today, we are going to describe each of these categories and discuss their importance and usefulness in advertising.
    The first category, the print media, consists of printed information sources; in other words, newspapers and magazines. For the advertisers, each of these has certain advantages and disadvantages. Let’s talk first about newspapers, which receive more money from advertisements each year than any other medium. This is because newspaper advertising has several outstanding advantages. First of all, nearly everybody reads newspapers. Therefore, newspaper ads reach huge numbers of people. Moreover, newspapers are generally local. This allows small, local businesses to advertise directly to their potential customers. Third, newspaper advertising is relatively cheap; so the ad can be as long as the advertiser wants, and it can also be repeated. On the other hand, newspaper ads have no color, and they are not very exciting or attractive. Instead, you find these ads in the second type of print medium, magazines.
    [18] For the advertiser, the greatest advantage of magazines is that they have specialized groups of readers. In other words, the people who read Car and Driver are probably not the same people who read Glamour, which is a women’s magazine, or The New Republic, a political magazine. Therefore, advertising in a magazine allows a business to direct its ads to the people who are most interested in the product The big disadvantage of magazine advertisement is that it can be very expensive, especially in magazines like Playboy or National Geographic,
    Let’s move along now and talk about the broadcast media, by which we mean radio and television. These also have both advantages and disadvantages. First, radio. Radio has two of the same advantages as newspapers: Almost everybody listens to it, and it’s usually local. The disadvantages of radio ads are that they must be short and that they are not permanent in the way printed ads are. Second, television. Of all the media, TV, with sound, movement, and color, is the most dramatic, so the ads are easy to remember. On the other hand, ads on TV are enormously expensive.
    Last category, direct media. [19] The most common direct media is the mail, and direct mail advertising is a very big business. Even if you have only lived in this country for a short time, you have probably already received advertisements in the mail. The advantage of advertising by mail is that the ad goes directly to the potential customer’s hands. However, many people don’t bother to read these ads; in fact, we call them "junk mail" and often throw them away without even opening the envelope.
    16. What is the most important decision a company has to make regarding advertising?
    17. What are the three categories of media?
    18. What is the greatest advantage of magazines?
    19. What is the most common direct media?