Structured programming practices (1) rise to Pascal, in which constructs were introduced to make programs more readable and better (2) . (3) provided a combination of assembly language and high-level structure to create a general-purpose language that could be used from system to application programming. Next came object orientation, which is (4) of a methodology and design philosophy than a language issue. This is (5) by the addition of so-called OO extensions to current languages, such as application.

（4）（）

A.more

B.little

C.amatter

D.important

变配电所中断路器的合闸、跳闸电源时操作电源。继电保护、、信号设备使用的电源不是操作电源。