主从句为何会都有连词

中考句子：

Have you ever waited in the lunch line only to find when you get to the front that you don’t like what they’re serving?

请问老师，这个句子为何有两连词when和that？

句子中的 that 引导宾语从句，when 引导时间状语从句——两个从句也可以交换地方：

Have you ever waited in the lunchline only to find when you get tothe front that you don’t like whatthey’re serving?

= Have you ever waited in the lunchline only to find that you don’t like whatthey’re serving when you get to thefront?

你是不是有过如此的历程：排队等着吃午餐，结果当你到达前面时却发现他们提供的饭菜你不喜欢？