Gerontics
n. 老年学, 老年医学
🗣️ 情景例句
So long.
再见。
I recognize that he is more clever than I am.
我承认他比我聪明。
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。