乘坐飞机之前，我们都应该要去了解清楚相关的规定要求，避免触犯了相关规定，严重还会面临牢狱之灾。比如这个男子一样，乘坐飞机的时候居然想要打开舱门，幸好被空姐看到阻止了。
I am trying to get a list of parents where the child collection does not contain an item of a specific type.The LINQ equivalent would be something like:
加载中,请稍侯......