Ratholite
针钠钙石
🗣️ 情景例句
No,
记不起来了。
Do not sell the bear's skin before you have caught the bear.
熊未到手休卖皮（勿过早乐观）。
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。