1 Essentially,a theory is an abstract,simbolic representation of what is conceived to be reality
一个理论本质上是对事实抽象的符号表述
2 Long before children are able to speak and understand a language, they communicate through facial expressions and by making noises
很长时间里，孩子们通过脸部表情和发出声响进行交流，直到他们能够说话和理解一们语言。
3 Thanks to modern irrigation, crops now grow abundantly in areas where once nothing but cacti and sagebrush could live
多亏了现代的灌溉技术，在曾经只有篙类植物可以生长的土地上，如今庄稼富产。
