"I could prove my origin not as readily as thou didst."

You and I will go to the cave, and you will prove your origin there - or die.

I realize there is no way we can prove our origin.

Above all, X-ray examination of the alien weapon would prove its non-human origin.

But so far none had any difficulty in proving their human origin.

This is issued to any person currently holding a non-Indian passport, who can prove their Indian origin up to three generations before.

The nodules served to prove that they were not stolen animals and to prove their origin.

A pity, I think, for once we capture one of those fellows we can definitely prove his origin and his nationality to the world.

And of course it's giving us a chance to characterize the singularity, to prove its origin.

Since these products can be freely imported, proving their origin is apparently unnecessary, but there are still some doubts about this facilitating measure.