A、9. B、10. C、11. D、12. C选项都是数字。从Eleven of the top 15 of the outstanding football earners are under the age of 30，可以得知是11。

M: Jenny, what do you think a millionaire should be tike?
W: Well, a millionaire is someone who owns a huge wealth of oiI wells, railroad shares, property, banks or the size of their factories and staff. The giant industrial magnate— Ford, Rockefeller, etc.
M: But today, many of the leading millionaires are not connected with any business production. They are stars who appear in films, play sports, speculate in property or sing rock and roll music.
W: That’s not strange. I just wonder what kinds of stars earn most.
M: The sports stars. They are not only paid for appearing in various sports and doing well at a professional level, but they earn huge sums from advertising endorsements, appearance money, and alliance with sponsors.
W: How rich are they?
M: Michael Jordan, the leading basketball player in the United States used to earn $16 million in addition to his $30 million salary for the endorsements he agreed to.
W: Wow! What about football stars? Do they earn as much?
M: The leading football players are some of the outstanding sports earners in the world. Business Age magazine listed them recently, and the top four were the stars from Brazil.
W: I think these new millionaires are much luckier than the Ford generation, because they are still quite young when they become millionaires.
M: That’s right. Eleven of the top 15 of the outstanding football earners are under the age of 30.
W: I wish I could be as rich as them when I am 91.