【单选题】The train is running fifty miles___.
【单选题】The train is running ______120 kilometres an hour.
【简答题】The train is running fifty miles
______ hourA. a B. an C. the D. /
【单选题】80年代,哪个国家发现的第一例艾滋病()
【单选题】The train is running fifty miles().
【单选题】往复式压缩机与往复泵相同之处是 () 。
【判断题】烟气较空气轻而飘与上部,贴近地面撤离是避免烟气吸入、滤去毒气的最佳方法