Lesson 12 Banks and their customers
by GORDON BARRIE and AUBREY L. DLAMOND
from The Consumer Society and the Law
12-1. When anyone opens a current account at a bank, he is lending the bank money, repayment of which he may demand at any time, either in cash or by drawing a cheque in favour of another person.
【讲解】repayment of which…another person为非限制性定语从句，which代表money。repayment of which在定语从句中作demand的宾语。
repayment：偿还，付还（when you pay back money that you have borrowed），
bonds due for repayment到期应偿还的债券
demand repayment of the stolen money 要求归还被窃钱款
12-2. Primarily, the banker-customer relationship is that of debtor and creditor—who is which depending on whether the customer's account is in credit or is overdrawn.
【讲解】that替代relationship，以避免重复。who is which depending on…overdrawn乃独立主格结构，进一步说明破折号之前的句子。who is which是现在分词短语depending on…overdrawn的逻辑主语。which代表debtor或creditor，意为“谁是债务人，谁是债权人”。whether…is overdrawn作on的宾语。
overdrawn：透支的（if you or your account is overdrawn, you have spent more than you had in your account and so you own the bank money），
interest charged on overdrawn accounts对透支账户所收的利息。
12-3. But, in addition to that basically simple concept, the bank and its customer owe a large number of obligations to one another.
owe：应给予；应该（或有必要）做（to feel that you should do sth. for sb. or give sb. sth. , because they have done sth. for you or given sth. to you），
owe sb. thanks 应向某人致谢
I owe him a letter. 我应该给他写一封信。
You owe yourself a subscription. 你该给自己订阅一份。
obligation：（法律上或道义上的）责任，义务（a moral or legal duty to do something），
a legal obligation to serve in the armed forces 服兵役的法律责任
the obligations of a citizen 公民的义务
fulfill every obligation 尽到每一责任
undertake new obligations 承担新的责任
feel an obligation to do sb. 感到对某人有责任