title: Get a IEnumerable<T> from a IEnumerable<IEnumerable<T>>
body: <p>public class Item
      {
          ...
      }</p>
  
  <pre><code>public class Order
  {
      public List&lt;Item&gt; Items
      ...
  }
  
  public class Customer
  {
      public List&lt;Order&gt; Orders
      ...
  }
  </code></pre>
  
  <p>Now, using LINQ I need to get all items that a customer bought. How can I?</p>
  
  <p>I tried something like <code>var items = from o in cust.Orders select o.Items;</code> but result is <code>IEnuberable&lt;List&lt;Item&gt;&gt;</code> and I wanna just one <code>IEnumerable&lt;Item&gt;</code>.</p>
  
  <p>I'm asking here to try to avoid coding 2 loops.</p>