Phugoid
长週期振动
🗣️ 情景例句
I think I know you. Aren't you...?
我觉得我认识你。你是……吗？
If I went with you,I'd have to be back by six o'clock
如果我与你一起去了，我将不得不在6点钟回来。
and then there are three thousand million other Milky Ways, or galaxies, in the universe.
况且在宇宙中还有30亿个天河，即银河系。