Think twice before you swat a fly or squash a bug: A newstudysays insects contribute more than $57 billion (euro47 billion)ayear to the . economy.当你挥动苍蝇拍想要打死一只苍蝇或臭虫时,
英语科普类文章1 听点小音乐 轻松学分数 Stuck on a tricky math problem? Start clapping. Grade school kids who learned about fractions through a rhythm-and-music-based curriculum outperformed their peers in tradit