An architectural Style defines as a family of such systems in terms of a (71) 、of structural organization.More specifically an architectural style defines a vocabulary of
(72) and connector types, and a set of (73) on how they can be combined. For many styles there may also exist one or more (74) that specify how to determine a system’s overall properties from the properties of its parts. Many of architectural styles have been developed over the years.The best-known examples of (75) architectures are programs written in the Unix shell．

A．metadata
B．components
C．models
D．entities

铣削多头螺旋槽时，每铣好一条螺旋槽后，应使工作台（）后再退刀。

A.下降一段距离

B.向前一段距离

C.向后一段距离

D.上升一段距离