有的分程控制系统有安全区间，其作用是（）
A、防止超压
B、避免阀门频繁动作
C、避免阀门同时动作
D、仪表保护
参考答案：B
______, the pay isn't attractive,though the job itself is quite interesting. [ ]
A. Generally speaking
B. On the contrary
C. In particular
D. To be honest
EB所包含的内容有网上交易，SCM、CRM和OPS等等.
