（）和（）是海洋环境中（）和其他养分主要的人为来源。
广告视觉传达在历史上发展速度最快的媒体形式是（）。
盐酸是由下列哪种细胞分泌的（） ["胃腺的主细胞","胃腺的粘液细胞","胃腺的壁细胞","幽门腺的G细胞"]
2015年12月25日，是川藏、青藏公路建成通车60周年纪念日。从“一不怕苦，二不怕死”到“顽强拼搏，甘当路石”、“军民一家，民族团结”的“两路”精神，流传神州大地。“两路”精神（）。 ["随着时代发展而得到继承与发扬","是改革开放伟大实践的产物","是社会发展进步的根本动力","成为每位中国人的强大精神支柱"]
Which two statements are true about IS -IS routing?（） [" Based on the default timers, OSPF d etects a failure faster than IS - IS does."," OSPF default timers permit more tuning than IS - IS does."," IS - IS is more efficient than OSPF in the use of CPU resources."," OSPF is more scalable than IS - IS because of its ability to identify normal, stub, an d NSSA areas."," IS - IS and OSPF are both Open Standard, link - state routing protocols which support VLSM."]
按照服务器的外观和安装结构的不同，服务器可分为
