we do not know when man first began to use salt,but we do know that it has been used throughout his
问题描述：
we do not know when man first began to use salt,but we do know that it has been used throughout his
这是什么意思!
答
We do not know when man first began to use salt,but we do know that it has been used throughout his history.
谁都不知道,人类是什么时候开始食盐的.但我们的确知道,食盐已经贯穿于整个人类历史.