【正确答案】 B

【答案解析】[听力原文]
   Spain's King Juan Carlos, being an emperor for 32 years, turns 70 Saturday. But after years of definite over-praise among Spaniards for putting down an attempted and sudden change of government in 1981, he's recently faced more difficult times. Small groups of leftists have burned his photo, and criticism has also come from the right with one leading conservative radio host calling for him to resign. Juan Carlos fired back with a rare public defense of his ruling in a recent speech. "It's been the longest period of stability and prosperity in Spain ever in a parliamentary monarchy," the king said.
   How long has Juan Carlos been King of Spain?
信息明示题。由Spain's King Juan Carlos, being an emperor for 32 years, turns 70 Saturday. 可知，西班牙的国王胡安·卡洛斯已经在位32年了，故选B。