夜晚北京地区能够看到的最亮恒星是()。 ["织女星","五车二","北极星","天狼星"]
辅助性商品群
()不是漏电保护器中间环节的组成部分? ["放大器","比较器","脱扣器","互感器"]
制定项目计划常用的方法有() ["工作分析结构表(WBS)","甘特图","ER图","PERT图","CPM图"]
卡西尼号除探测了土星之外,还探测过哪颗行星?() ["金星","火星","木星","水星"]
大连港与美国的()、休斯敦港,加拿大的(),日本的北九州港、横滨港、伏木富山等港结为友好港。