I suppose we were misled by Earth custom, which doesn't allow women much hand in the affairs of the military.

"You seem to understand Earth customs very well."

But Earth customs, I knew, were quite different.

It's one of those primitive ancient Earth customs that human culture Finally outgrew.

"Probably an Earth custom," I told him and let it go at that.

They find that the Cygnoids have much to learn about Earth customs.

You've also investigated Earth customs, history, and politics in some detail.

Being from the magical world, she is very naive about Earth customs.

Have I done something contrary to your Earth customs?

"An old Earth custom," Kirk explained, "abandoned long ago for its negative effects on one's health."