try every possible means 为什么是means 不是mean.不是说有every each修饰时用

try every possible means 为什么是means 不是mean.不是说有every each修饰时用 every后面不是加单数可数名词,为什么要说every means 而不能说every mean? every possible means The government____ that they will try every possible means t every possible means 是用单数还是复数 为什么是means of transportation不是mean of transportation Every possible means -----,but none proves successful. Every possible means ___.was tried has been tried.为什么不能选 Was Every possible means _____ to prevent the pollution,but the 选择：Every possible means ( ) to prevent the air pollution by every means Every means ____tired?选什么?为什么?