[填空题]Anyone who opens a current account at a bank he is lending the bank money, repayment of which he 1.______ may demand at any time, either cash or by drawing a 2.______ check in favor of another person. Primarily, the bankercustomer relationship which is of debtor and creditor— 3.______ which is depending on whether the customer’s simple account is in credit or is overdrawn. But, in addition on that basically simple concept, the bank and 4.______ its customer owe a large number of obligations to one and another. Many of these obligations give rise to problems 5.______ and complications, but a bank customer, unlike, say, a buyer of goods, cannot complain that the law is loaded against him. The bank must obey its customer’s instructions, and not those of anyone else. When, for example, a customer fir