时间总是跟我们在我们的生活。我们不能看到它。但我们可以感觉到它。
Time is always with us in our live. We can not see it. But we can feel it go by.
纱裙一直从脸罩到脚；透过它，她能看得见外面，但我们不能看到她的脸。
The veil came from her head to her feet; she could see out through it, but we could not see her face.
当然我们还不能看到，三元函数的图像，因为它处在一个四维空间里。
Except, of course, we haven't see the graph of a function of three variables because that would live in 4-dimensional space.
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