[单选] 安全工器具经试验合格后，应在不妨碍绝缘性能（）的部位粘贴合格证。

胰腺癌病人最常见的首发症状是（）。 黄疸。 食欲不振。 乏力消瘦。 消化不良。 上腹痛及上腹饱胀不适。 为何要进行保险投资？ 在“同伴教育对糖尿病患者服药依从性的影响”研究中，“同伴教育”是（）   因变量。  干扰变量。  自变量。  外变量。  控制变量。 人本治疗模式的治疗特点？ Acme Nutrition manufactures a wide variety of vitamin supplements. It has a single manufacturing facility with 3 regional warehouses and 16 district sales offices. Currently the manufacturing facility requires 210 IP addresses; each warehouse requires 51 IP addresses; each district sales office requires 11 IP addresses; and the IP WAN requires 38 IP addresses. if Acme Nutrition plans for 20 percent growth in facilities, how many Class C subnets will the district sales offices require?（） 19 (3 from the warehouse range and 16 from a separate Class C address)。 19 (3 from the warehouse block, 15 from a separate Class C block and 1 from the IP WAN block)。 20 (4 from the warehouse range,15 from a separate Class C block and 1 from the IP WAN block)。 16 (3 from the warehouse range and 13 from a separate Class C address)。 安全工器具经试验合格后，应在不妨碍绝缘性能（）的部位粘贴合格证。