【判断题】作用在同一物体上的两个力,使物体处于平衡的必要和充分条件是:两个力大小相等、方向相反、沿同一条直线。
【判断题】作用在同一物体上的两个力,使物体处于平衡的必要充分条件是:这两个力大小相等、方向相反,沿同一条直线。
【单选题】肝转移癌表现为不规则强回声,后伴声影,关于可能的原发癌,说法错误的是
【单选题】骑自行车应当在( )内通行。在没有非机动车道的道路上,骑自行车应当在( )通行。
【单选题】The reason _____ he refused to attend the meeting was that they didn't give him an invitation earlier.
【单选题】Some countries will not let foreigners in if their _______ is valid for less than six months.
【单选题】The reason _____ he refused to attend the meeting was that they didn’t give him an invitation earlier.