Tabs on leads section, are the customizable?

Tabs on leads section, are the customizable?

Hello All,

When I am entering my leads (or accounts, or contacts for that matter), there are 3 or 4 colums automatically there, such as "company" and "email address" and "phone number"  however-- how can I get 'Country' up there?  Without being able to add this column I may have to quit Zoho and move to a new CRM

(I have the entrepreneurial 3 person free trial version)

Thanks in advance for the quickest response posssible!

Regards,
Jessica