If your question is about how to add Google AdSense to your Hubs here on HubPages, then the answer is that you don't copy and paste any code.
All you have to do is to type your AdSense pub code into the affiliate field. Click on "My Account". Click on "Affiliate Settings", then type in your pub code. HubPages automatically place relevant Google Ads in the most profitable places on your Hubs for you.