Ifelse
如果…否则
🗣️ 情景例句
No, no. Please, go ahead.
不用 ，不用。你走吧。
He laughs best who laughs last.
谁笑在最后，谁笑得最好。
It was the idea of supporting a craft on a 'pad',or cushion, of low-pressure air, ringed with a curtain of higher pressure air.
用一个气垫来支撑船体，低压空或软垫，软垫周围用高压空气环绕。