1 Dear Mr. Gordon: We are at a loss to understand why you still have not cleared your __①___ of $3,105, which is now more than two months overdue. As we have ___②__ for some time, we have not pressed for payment. __③___, we must now insist that either you __④___ the account within the next ten days or offer a reasonable explanation. Otherwise, we shall have no choice ___⑤__ to hand the matter over to a collection agency. We would hate to lose a valued friend, and we hope that some action on your part will make this step unnecessary. Regards, Justin Yang