送交者: 老中乙号 于 2007-09-13, 11:41:56:

回答: need relative motion with respect to the air, too bad which moves with the earth 由 赤城 于 2007-09-13, 11:40:35:

• all depend on your reference frame - 赤城 (223 bytes) 2007-09-13, 11:50:07 (170181)

加跟贴