Ech
abbr. echelon 梯形，梯次编队
🗣️ 情景例句
We had a good day.
我们今天玩得很开心。
He's absorbed in his book.
他全神贯注地读书。
If people don't stop polluting the seas and rivers, there will be no fish left.
如果人们不停止污染海洋和河流的行为，那么，就没有鱼会留下来了。