This was invitation enough.求此句中invitation用法

This was invitation enough.出自傲慢与偏见名著 She was reluctant to accept his invitation.\x0c此句中不定式做什么成分?\ invitation This was invitation enough 我的问题是就光从语法上看 为什么不加an呢? invite invitation 用法.区别? This is Mary's invitation 翻译一句Mary was eager to have her invitation to her birthday pa invitation letter a invitation还是an invitation invitation to 还是 invitation for? 英语翻译our invitation should be enough to receive an applicant This is an invitation to look foolish请问这里的invitation怎么理解,