以经济建设为中心是兴国之要，（）仍是解决我国所有问题的关键。 民族复兴。 改革开放。 发展。 法治。
史学理论
使君从南来，五马立踟蹰。使君遣吏往，问是谁家姝？
“秦氏有好女，自名为罗敷。“
“罗敷年几何？”
“二十尚不足，十五颇有余。”
“使君谢罗敷，宁可共载不？”
罗敷前置辞：“使君一何愚！使君自有妇，罗敷自有夫。”
解释这段诗句中划横线字的含义。
You have configured a Cisco Catalyst switch to perform Layer 3 routing via an SVI and have assigned that interface to VLAN 20. To check the status of the SVI， you issue the show interfaces vlan 20 command at the CLI prompt. You see from the output display that the interface is in an "up/up" state. What must be true in an SVI configuration to bring the VLAN and line protocol up？（） The port must be physically connected to another Layer 3 device.。 At least one port in VLAN 20 must be active.。 The Layer 3 routing protocol must be operational and receiving routing updates from neighboring peer devices.。 Because this is a virtual interface， the operational status will always be in an "up/up" state.。
Assume the scoped attribute priority does NOT yet exist. Which two create and set a new request-scopedattribute priority to the value "medium"？（） A.${priority = ’medium’}。 ${requestScope[’priority’] = ’medium’}。 <c：set var="priority" value="medium" />。 <c：set var="priority" scope="request">medium</c：set>。 <c：set var="priority" value="medium" scope="request" />。
下列选项属于外部学习动机的是（）。
