有风点源正态烟羽扩散模式计算的污染源下风向污染物浓度C指取样时间( )的浓度,mg/m3。
A.0.5h
B.24h
C.小于24h
D.8h
参考答案:C
Networks can be interconnected by different devices. In the physical layer networks can be connected by (31) or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches which operate at data link layer. They can accept (32) , examine the MAC address and forward the frames to a different network while doing minor protocol translation in the process. In network layer, we have routers that can connect two networks. If two networks have (33) network layer, the muter may be able to translate between the packer formats. In the transport layer we find transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message (34) . As an example, gateways between Internet e-mail and X.400 e-mail must (35) the e-mail message and change various header fields.
A.analyze
B.parse
C.delete
D.create
事业单位原聘用制女干部退休待遇核定有什么规定?