title: Selecting several class properties in one query
body: <p>The following code takes a collection of class C and creates a collection consisting of the values of two properties A and B. A and B are put inside the same collection:</p>
  
  <pre><code>class A
  {
      public int x { get; set; }
  }
  class B
  {
      public int x { get; set; }
  }
  class C
  {
      public A A { get; set; }
      public B B { get; set; }
  }
  
  ..........
  
  var items = new List&lt;C&gt;()
                  {
                      new C()
                          {
                              A = new A() {x = 1},
                              B = new B() {x = 2}
                          },
                      new C()
                          {
                              A = new A() {x = 3},
                              B = new B() {x = 4}
                          },
                  };
  
  var qA = from item in items
           select (object)item.A;
  var qB = from item in items
           select (object)item.B;
  var qAll = qA.Concat(qB);
  </code></pre>
  
  <p>Is it possible to do this with one query?</p>