external source短语²⁵⁰¹⁶ 基本例句 外部信源 However, Mr Hansen said it was unlikely the Northern Lights could create the optical effect on its own. Instead the aurora might be bouncing off an external source like a satellite or an airplane. 然而，后来经调查，他排除了该现象是北极光自身产生的推测，他认为这可能是一个物体例如卫星或飞机反射极光产生的影像。 yeeyan