The Simple Network Management Protocol (SN
题型：单项选择题
问题：
The Simple Network Management Protocol (SNMP)is an (66) protocol that facilitates the exchange of management information between (67) . It is part of the Transmission Control Protocol/Internet Protocol(TCP/IP) protocol suite. SNMP enables network (68) to manage network performance, find and sole network problems, and plan for (69) An SNMP -managed network consists of three key components: managed devices , (70) ,and network -management systems .
A. Physical Layer B. Link LayerC. Network Layer D. Transport Layer
应形成环己基过氧化氢，该过氧化物在Au/TS1催化作用下受热分解，生成环己醇和环己酮(O)。由于环己醇、环己酮比环己烷更容易被氧化，因而有许多副产物(如己二酸及一些酯类化合物)生成。
目标产物的总收率(y)却逐渐降低，其可能的原因是 。