#customers tr.alt td 
{
color:#000000;
background-color:#EAF2D3;
}
#customers is the id of a table.  Since I'm new to CSS, is the above method a valid selector? In CSS I have only found element element selectors.  But here in the question there are three elements: table tr td.  I have not found an example of the three element selector.  So does the three element selector exist in CSS?
 
     
     
     
    