invitation是名词用于形容词前后或介词后,为什么还有 write an invitation letter

an invitation letter please write an invitation letter to you oen friend 为什么用invi Directions: Write an invitation letter by using the informat Write an invitation letter according to the following inform You are required to write an invitation letter Directions:Write an invitation letter by using the informati 英语作文write an invitation how to write an invitation invitation letter invitation 是可数名词吗? a invitation还是an invitation invitation