USD or EURO?

hi again :D


I live in South America, where i can easily change my currency to dollars or euros...what currency would be better accepted in UK.

of course I can't get GBP in my country

You will be able to change Dollars or Euros at any bank in the UK.
The Euro can also be used in the UK but is rare and unpopular, likely to be refused at most shops.

and dollars are more widely accepted or is the same as euros?

Maybe the odd top shops will accept Dollars, but the vast majority will not.
Change at a bank, but check their websites first as exchange rates vary a lot.

Either way, you'll have to exchange twice, so watch out for losses, but I don't see any British bank having restrictions on accepting or changing Argentine peso to pounds, so check that first.
If they do, you only have to change once.