how do you understand:"once the sands have run out of one's hourglass,they cannot be replaced."
问题描述：
how do you understand:"once the sands have run out of one's hourglass,they cannot be replaced."
答
字面上是说,一旦一个人沙漏里的沙子流完了,就再也不能再填满了.
就是说“光阴一去不复返.”
That means the same as "Time and tide wait for no man."
Once time past,it's gone forever.