WASHINGTON (AP) - Give a group of fourth-graders a map of the world and only half can label the North Pole, South Pole and equator. Ask them why rock 'n' roll has spread all over the world and 70 percent can tell you. The questions come from a national geography test given last year, the results of which were released Friday by the Education Department. When asked to label maps with the three major geographic features, only 54 percent of fourth-graders put all three in their proper places; but 70 percent knew that TV and radio helped popular music spread...