Phyllula
叶枕
🗣️ 情景例句
I have room reserved.
我已订了房。
The radio is out of order.
这收音机坏了。
and by measuring the time interval between the taps and the receipt of the echoes, the depth of the sea at that point can be calculated.
测出回声间隔的时间，便可算出该处海洋的深度。