读我国局部地区图及四地年降水量 （单位：毫米）统计资料，回答1～3题。

1．形成东西方向年降水量差异的主要因素是 [ ]

A．海拔

B．距海远近

C．气温

D．地表植被

2．该区域的自然灾害主要是[     ]

A．沙尘暴

B．泥石流

C．地震

D．水土流失

3．关于a河段的叙述，错误的是 [     ]

A．流域面积扩大，河水水量显著减少

B．工农业用水较多

C．地势平坦，水流平缓

D．下游纬度高，有凌汛现象

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．event-based
B．object-oriented
C．pipe-and-filter
D．layered