解释语法We will never forget the days ____we spent together,sing

1 I will never forget the days ____we spent together.A that I will never forget the days that we spent together in the c I will never forget the days when we spent together in the c I will never forget the days-----we spent together in the fo I will never forget the days _______ we spent together.  I will never forget the happy days we spent together中间的先行词填什 We will never forget the day,_______ we spent together. 语法 I will never forget the days ___ we worked together. I will never forget these days (which )we spent together.为什么 .I’ll never forget the days ______ we spent together in the i'll never forget the days we spent together on the beach la I'll never forget the days that/which we spent together.