I did the following query:

var list = from book in books
          where book.price > 50
          select book;

list = list.Take(50);

I would expect the above to generate something like:

SELECT top 50 id, title, price, author
FROM Books
WHERE price > 50

but it generates:

SELECT
[Limit1].[C1] as [C1]
[Limit1].[id] as [Id], 
[Limit1].[title] as [title], 
[Limit1].[price] as [price], 
[Limit1].[author]
FROM (SELECT TOP (50) 
             [Extent1].[id] as as [Id], 
             [Extent1].[title] as [title], 
             [Extent1].[price] as [price], 
             [Extent1].[author] as [author]
      FROM Books as [Extent1]
      WHERE [Extent1].[price] > 50
     ) AS [Limit1]

Why does the above linq query generate a subquery and where does the C1 come from?