Commercial banks accept deposits and provide security and convenience to their customers. Part of the original purpose of banks was to offer customers safe keeping for their money. By keeping physical cash at home or in a wallet, there are risks of loss due to theft and accidents, not to mention the loss of possible income from interest. With banks, consumers no longer need to keep large amounts of currency on hand; transactions can be handled with checks, debit cards or credit cards, instead.
   Commercial banks also make loans that individuals and businesses use to buy goods or expand business operations, which in turn leads to more deposited funds that make their way to banks. If banks can lend money at a higher interest rate than they have to pay for funds and operating costs, they make money.

Notes:

(1) commercial banks 商业银行 

a. Commercial banks have been a major source of loans to agriculture.  

商业银行曾是对农业的主要贷款来源。

b. Our bank will pay the highest interest rate permitted for commercial banks.  

我们的银行支付商业银行所准许给的最高利息。

c. Part 1 introduces the ascertainment of key stuff in state - owned commercial banks.  

第1部分介绍了 国有 商业银行核心员工的界定。

(2) deposits n. 存款, 储蓄

a. Avoid deposits in excess of £20,000 in any one account.  

单一账户存款勿超过两万英镑。

b. Deposits of plaque build up between the tooth and the gum.  

牙齿和牙龈之间会滋生牙斑。

c. Long-term stock market investments have produced superior returns compared with cash deposits.  

股票市场长期投资的收益比现金存款要高。

(3) wallet n. 钱包 

a. I got out my wallet and began to dole out the money.  

我掏出钱包开始发钱。

b. I felt for my wallet and papers in my inside pocket.  

我在里兜里摸钱包和证件。

c. He took out his fat wallet and peeled off some notes.  

他掏出鼓鼓的钱包，抽出几张钞票。

(4) debit cards n. 借记卡

a. Some schemes issue customers with debit cards linked to their m - banking accounts.  

一些方案向消费者发放和他们手机银行帐号挂钩的贷记卡。

b. Debit cards, also known as check cards, do not have interest charges.  

借记卡也被称为(银行的)支票保证卡, 不收取任何的利率。

c. Check your ATM, credit and debit cards before you leave.  

出发前检查你的ATM卡, 信用卡和借记卡。

(5) credit cards n. 贷记卡                      

a. All major credit cards are accepted at our hotels.  

我们的饭店接受所有主要的信用卡。

b. Credit cards eliminate the need to carry a lot of cash.  

有了信用卡就用不着携带很多现金。

c. Net surfers can use their credit cards to pay for anything from toys to train tickets.  

上网者能用信用卡购买从玩具到火车票的任何东西。

参考译文：

商业银行接受存款并为客户提供安全和便捷。银行最初的一部分目的是安全保存客户的资金。在家中或钱包里保存现金存在因盗窃和事故而丢失的风险，更不用说还会损失可能的利息收益。有了银行，客户无需持有大量现金，交易也可以通过支票、借记卡或贷记卡处理。

    商业银行还为个人和企业购买商品或扩大经营规模提供贷款，从而使得更多存款进入银行。如果银行的贷款利率高出必要的存款利率和经营成本利率，银行就盈利了。