收集设计信息的途径有： ①用户调查； ②专家咨询； ③收听收看广播电视； ④查阅图书

下列哪种说法是正确的

A．发病率指观察期内观察人群中新病例发生的频率

B．罹患率指观察期内观察人群中新旧病例所占的比例

C．患病率指观察期内观察人群中新病例发生的频率

D．患病率指观察期内观察人群中旧病例发生的频率

E．发病率指观察期内观察人群中新旧病例发生的频率

竞技健美操单人及混双项目的比赛场地面积是（）.

A.6*6M

B.8*8M

C.10*10M

D.12*12M

VB中的控制结构包括顺序结构、分支结构 【10】 结构。

The software architecture of a program or computing system is the structure or structures of the system, which comprise software （1）, the externally （2）properties of those components, and the relationships between them. The architecture is not the operational software. Rather, it is a （3） that enables a software engineer to: analyze the （4）of the design in meeting its stated requirements, consider architectural alternatives at a stage when making design changes is still relatively easy, and reduce the（5） associated with the construction of the software.

（2）是（）

A.visible

B.reliable

C.secure

D.robust