题目

    Last Wednesday, about 7,400 American bankers went back to school again． This time they did not go to learn－they went to teach．  61  1997, the American Bankers Association has sponsored Teach Children to Save Day． Every April 26, bankers across the USA teach over l．5 million primary and secondary school students how to handle  62  money．      In the USA, children, especially teenagers, are often big spenders． In 2013, for example, American teenagers spent $175 billion． This is  63  average of $104  per week per teenager,  Few teenagers have any savings在哈尔滨的中央大街的步行街同侧有6块广告牌，牌的底色可选用红、蓝两种颜色，若要求相邻两块牌的底色不都为蓝色，则不同的配色方案共有（ ）A. 20 B. 21 C. 22 D. 24