【单选题】I don‘t know when she ___ back, but give her the message if she comes in before two.
【判断题】《 2010通则》中11个贸易术语买方承担责任最大的是EXW,最小的是DDP。
【判断题】单作用叶片泵的转子每转 1周,每个密封容积完成2次吸油和压油。
【单选题】比特(Bit)是下列哪一层的协议数据单元( )。
【单选题】When doves are about two weeks old, they are covered with grey feathers and are ready to try their wings.