根据《建筑设计防火规范》厂房(仓库)的耐火等级与构件的耐火极限规定,耐火等级为一级的梁的耐火极限为()。
A.1.0h
B.1.5h
C.2.0h
D.3.0h
参考答案:C
—Where is Jenny? I’m looking for her__________.
— I saw her in the library just now.
A. nowhere B somewhere C. anywhere D. everywhere
何为通道间隔?并说明DWDM系统采用各种配置通道间隔各为多少?