If a certificate authority trustpoint is not configured when enabling HTTPS and the remote HTTPS server requires client authentication，connections to the secure HTTP client will fail. Which command must be enabled for correct operation？（） ["ip http client secure-ciphersuite 3des-ede-cbc-sha","ip https max-connections 10","ip http timeout-policy idle 30 life 120 requests 100","ip http client secure-trustpoint trustpoint-name"]
1660SM4.x版本设备中所用的HOA共有（）个，它的主要作用（） ["1","96","64","高低阶通道之间的适配","完成交叉连接","140MPDH信号接口"]
铁路旅客平均行程是指铁路运送的每一位旅客的平均运输距离（km）。（）
教育公共关系的传播具有以下特征（）。 ["以教育组织目标为主导","以谋求教育组织的发展为目的","传播具有双向性","传播具有中介性"]
能量流
简述屠能的农业区位理论。
