按字母顺序整理:
具有延迟计算的运算符
Cast,Concat,DefaultIfEmpty,Distinct,Except,GroupBy,GroupJoin,Intersect ,Join,OfType,OrderBy,OrderByDescending,Repeat,Reverse,Select,SelectMany,Skip,SkipWhile,Take,TakeWhile,ThenBy,ThenByDescending,Union,Where,Zip
立即执行的运算符
Aggregate,All,Any,Average,Contains,Count,ElementAt,ElementAtOrDefault ,Empty,First,FirstOrDefault,Last,LastOrDefault,LongCount,Max,Min,Range ,SequenceEqual,Single,SingleOrDefault,Sum,ToArray,ToDictionary,ToList,ToLookup