协方差为正表示两种资产的报酬率呈同方向变动。（）
Virtual PortChannels （vPCs） allow links that are physically connected to two different Cisco switches to appear to a third downstream device as coming from a single device and as part of a single port channel. Which of the following are components of a Virtual PortChannel system？ （） Two peer devices： the vPC peers of which one is primary and one is secondary and are part of a vPC domain.。 A Layer 3 Gigabit Ethernet link called peer-keepalive link to resolve dual-active scenarios。 A redundant 10 Gigabit Ethernet PortChannel called a peer link to carry traffic from one system to the other when needed。 vPC member ports forming the PortChannel。 A dot1q trunk between the vPC peers。 A management port that can be used as peer-keepalive link to resolve dual-active scenarios.。
设备的最优更新期选择，应以设备的费用最小为准，这些费用是指（）。 一次性投资。 经营费用。 修理费用。 一次性投资和各年经营费用总和。
根据目前施行的学生体质测量方案，某大学男生肺活量体重指数是52，他的体质评分属于下列哪个评分标准？（） 优秀。 良好。 及格。 不及格。
投资组合所包含的资产种类越多，组合的总风险就越低。（）
先秦时期最重要的设计著作是（）
