Radioecho
无线电回波, 无线电反射信号
🗣️ 情景例句
I hope so.
但愿如此。
If you were to attend the banquet ,what would you wear?
如果你将出席宴会，你将穿什么？
Many strange new means of transport have been developed in our century,
本世纪已研制出许多新奇的交通工具，