电气设备着火后，切断电源要用适当的（），以防触电。
A. 绝缘工具
B. 消防设施
C. 防毒面具
D. 手工具
Which two statements about the diffserv model are true？（）
A. a class can be inentified as a single application .multiple applications with similar service nees.or be based on the source or destination ip addresses.
B. a drawback of the diffserv model is that it does not provide backward compatibility with devices that can only use the tos field.
C. diffserv uses the diffserv field in the MAC header to mark frames into behavior aggregates（BAs）
D. the diffserv field occupies the same eight bits of the mac header that were previously used for the tos field.
E. the first six high-order bits of the diffserv field are used to identify the resource reservation protocol（RSVP） value .
F. the primary goal of diffserv is scalabilty.
闸刀开关没有灭弧装置，只能控制4kW以下的小型电机或负载。
A. 正确
B. 错误
"理财金账户"中的相关活期子账户除了正常的存、取款外，还有其他功能吗？
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