Canceler
n. 消除器, 补偿设备
🗣️ 情景例句
But?
但是？
Old wood is best to burn,old book to read.
老柴好烧，老书宜读。
it is now possible not only to locate a shoal but to tell if it is herring, cod, or other well-known fish, by the pattern of its echo.
不仅能够确定鱼群的位置，而且可以根据鱼群回声的特点分辨出是鲱鱼、鳕鱼，这是人们所熟悉的其他鱼。