What is the material of the object behind the rubber gray object that is the same shape as the large metallic cube?
return the  rubber gray object  ;return the  large metallic cube ;return objects behind of #1 ;return shape of #2 ;return shapes of #3 ;return #3 where #5 is the  same as #4 ;return material of #6
['select', 'select', 'project', 'project', 'project', 'comparative', 'project']