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.

（2）（）

A.structure

B.structured

C.constructs

D.structures

男性，72岁，心肌梗死后反复出现频发室性期前收缩，3天来反复发作胸骨后疼痛伴晕厥，晕厥最可能的原因是（）

A.阵发性心房扑动

B.阵发性心房颤动

C.阵发性室上性心动过速

D.阵发性房性心动过速

E.阵发性室性心动过速