阅读下面这首宋诗，然后回答问题。

　　【注】①石湖：南宋诗人范成大( 1126 -1193)晚年去职归隐石湖（在今江苏苏州），自号石湖居士。②姜夔(1155 -1221)：字尧章，号白石道人，饶州鄱阳（今江西波阳）人。浪迹江湖，终生不仕。淳熙十四年(1187)夏，曾去拜见范成大，这首诗约作于此时。

这首诗描绘了一幅什么样的画面？是由哪些景物构成的？请简要叙述。答：                                                                        。

Astute service providers realize that the continued support of legacy X.25 and asynchronous network element using separate operations network is cost(16).For example,the maintenance of multiple networks can require additional staff. Often, this staff must be trained on multiple vendor technologies, sometimes requiring parallel groups specializing in each (17) .Hence, additional maintenance procedures must be maintained and administrative records are (18) .The duplication of transport facilities to carry (19)network traffic is an inefficient use of resources. And not surprisingly, more technologies installed in a central office means the necessity for more physical space, and an increase in power connections and power consumption migration of these (20) network elements to IP-based DCns is alogical strategy.

空白处（18）应选择（）

A.declined

B.proliferated

C.destroyed

D.produced