单选题 Yet slipping from popular culture is the wonder and beauty of the natural world. For every three nature-related words in hit songs of the 1950s, researchers found, there was only slightly more than one 50 years later. It is not a moment too soon that teenagers will be able to take a natural history test, given that for decades children have been able to name more video game characters than wildlife species.运用四级仔细阅读的技巧,根据所提供的文本材料,研究人员关于流行文化有何发现?( )