Probably men.

Evidently highly civilized.
Doubtless possessed of much valuable knowledge.

May be dangerous.

Catch them if possible; tame and train them if necessary This may be a chance to re-establish a bi-sexual state for our people." They were not afraid of us--three million highly intelligent women--or two million, counting only grown-ups--were not likely to be afraid of three young men.

We thought of them as "Women," and therefore timid; but it was two thousand years since they had had anything to be afraid of, and certainly more than one thousand since they had outgrown the feeling.
We thought--at least Terry did--that we could have our pick of them.
They thought--very cautiously and farsightedly--of picking us, if it seemed wise.
All that time we were in training they studied us, analyzed us, prepared reports about us, and this information was widely disseminated all about the land.
Not a girl in that country had not been learning for months as much as could be gathered about our country, our culture, our personal characters.