问题
单项选择题
The growth of switching has (135) a new generation of network management tools that help (136) cope with the challenges, (137) them to correlate device alarms in order to (138) pinpoint root causes, or to monitor service levels without depending on IP subnet schemes. These new tools have become essential to coping with the primary (139) effect of any treatment that significantly increases network flexibility: added complexity.
139（）
A.technicians
B.workers
C.salesmen
D.professors
答案
参考答案：B
解析：
交换技术的发展催生了新一代网络管理工具。这些工具有助于技术人员应付各种挑战，它们与设备报警相连能更好地查明根本原因，或者不依赖于IP子网配置来监控服务级别。对于解决因显著增加网络适应性(增加的复杂性)带来的主要的副作用的问题，这些工具是必需的。