An airship depends on a gas that is lighter than air. 而飞艇依靠的是一种比空气轻的气体。
It isn't as responsive to his thoughts as the puddle jumpers were, but then nothing will be unless the Air Force builds a new one from their schematics. 这感觉丝毫不能和他想念的小飞艇比，可一个飞艇都没，除非空军按他们的图纸造个新的。
