送交者: coubert 于 2009-11-13, 12:36:26:

回答: "I don't know how the forward propelling force is generated". hahaha 由 tinaliang 于 2009-11-13, 12:32:36:

• 好笑啊. 你俩文科的? (无内容) - tinaliang (0 bytes) 2009-11-13, 12:40:05 (385575)
  • My major is natural philosophy - gyro (52 bytes) 2009-11-13, 12:41:18 (385576)
    • you move forward by moving media around you backward, like swimming. (无内容) - tinaliang (0 bytes) 2009-11-13, 12:47:36 (385586)

加跟贴