【简答题】链传动的类型为_______链传动、起重链传动、_______链传动。
【单选题】Not until the press reported the pollution _________ why the water supply had been cut off.
【单选题】None of the five people killed by inhalational anthrax had been vaccinated against influenza
【单选题】下列VPN技术中,属于第二层VPN的有()
【单选题】Contemplation was _____ for action.
【多选题】下列VPN技术中,属于第二层的VPN的有
【单选题】四冲程柴油机将燃油凸轮向凸轮轴正车方向转动α,则喷油泵的供油提前角由β变化为()。
【多选题】下列VPN技术中,属于第二层VPN的有().