I need to know if the List I am working with contains only some specific values.

var list = new List<string> { "First", "Second", "Third" };

If I want to know if the List contain at least one item with the value "First" I use the Any keyword:

var result = list.Any(l => l == "First");

But how I can write a Linq expression that will return true/false only if the List contains "First" and "Second" values?