Think twice before you swat a fly or squash a bug: A new study says insects contribute more than $57 billion (euro47 billion) a year to the U.S. economy.

• 当你挥动苍蝇拍想要打死一只苍蝇或臭虫时，最好三思而后行。因为一项最新的研究结果显示，昆虫每年给美国经济带来的贡献竟然超过了570亿美元之多。