F2
[医] 第二子代
🗣️ 情景例句
Well keep in touch, ok?
保持联络，好吗？
Close your book,please.
请把书合上。
and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace.
因此，尽管制造这些工具的人的骨头早已荡然无存，但远古时代的石头工具却保存了下来。