Single Attribute defaults to radio button.

Hi I have a cart that require all attributes to show as a dropdown list. However some only have 1 attribute and these default to a radio button. Anybody any ideas on how to get it to default to a dropdown even if there is only one attribute to select?

Anybody any ideas on how to get it to default to a dropdown even if there is only one attribute to select?
There is nothing to drop down....
If these are "required" you could add a "please choose" or "select" option

ok how would I add this in for all dropdown menus? Bearing in mind all attributes have now been assigned to products.

create an option value as select or your choosen description
Add it to the single option items with a sort order to have it first and mark it as Default Attribute
to be Marked Selected: