Which statement correctly describes a situation in which VRFs are used in the data center?（） [" Partitioning of network resources is enabled."," VRFs cannot support path isolation from MAN\/WAN designs."," VRFs cannot be used to map a virtualized data center to a MPLS implementation."," VRFs do not allow for the use of application services with multiple access topologies."," An access design using a VRF allows for an aggregation layer service module solution."]
文字是能指实际上就是（）。
户外变压器二次侧用隔离开关时，其熔断器应装在（）之间。 ["隔离开关与低压绝缘子","变压器二次出线与隔离开关灯","隔离开关与低压避雷器","变压器二次出线与低压避雷器"]
界刺激与主体反应的关系不是简单的S-→R，而是S→AT→R， AT是主体同化刺激S于结构T的结果，A是大于1的系数。这是（）提出的学习的心理过程。 ["皮亚杰","赫尔巴特","奥苏贝尔","班杜拉"]
汉字在语音上代表（），在意义上代表（）。
谷物中的矿质元素有哪些？
