1.Banks were developed to keep people's money safe and to make it available when they needed it.开办银行是为了稳妥地保管人们的钱财，使他们在需要时能随时提取。
(1)此句中的动词不定式短语to keep people's money safe和to make it available作目的状语。
(2)to keep people's money safe:使人们的钱财安全
keep:to cause to continue in a state, condition, or course of action:维持：使…保持某一状态、情况或过程的动作
例如:attempt to keep the patient calm.
(3) to make it available:使存款随时可取
①make:to cause to act in a specified manner:造成，导致：以特定的方式引起行动
例如:Heat makes gases expand.
③available:adj.present and ready for use; at hand; accessible:现实可用的；可获得的
2.It isn't convenient for him to send money through the mail, so he goes to the bank and opens a checking account.通过邮局汇款使他感到不方便，因此，他到银行开了一个支票账户。
此句中的it为形式主语, 真正的主语是for him to send money…。
3.This check is as good as money to the owner of the company. 这张支票对公司的老板来说就跟真正的货币一样。
②as good as:与……几乎一样; 实际上等于
4.It's hard to imagine that people could do business without the services of a bank.很难想象出人们在没有银行服务的情况下做生意的情形。
①此句中的it是形式主语, 真正的主语是to imagine that…。