Antilitter
a. 防止(或劝阻)在公共场所乱丢杂物的
🗣️ 情景例句
That's fine. I'll await his return call.
很好。我会等他的来电。
Good luck to you.
祝您好运。
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。