Of the dozen or so times when a top ranked female tennis player played either a much lower ranked or handicapped male player, I think the male lost only once (1973 King vs Riggs, through there are claims that Riggs threw the match).

There exist sports where having XX chromosome is not a disadvantage. Male and female equestrians have been competing against each other in the Olympics since the modern Olympics began.

The issue of gender and ‘what makes a woman a woman’ in sports is not new. There are plenty of cases of men pretending to be women and claiming top prizes. I don’t envy the officials who have to do gender tests , as there are many people who are neither XX or XY.

EDIT: now that I’ve had some time to go though my sources a little better, I should correct a couple things. According to the Wikipedia article, females have won more than a couple matches against males, though all of those matches involved either a handicap or a much lower ranked male. The Williams sisters themselves only claimed they could beat any male outside the top 200 (but they both lost by a wide margin in friendly sets to #203).

Male and Female equestrians have only been competing against each other since 1952, and not since the beginning of the modem Olympics.

Yes. (Linked article is Korean)

Modern ondol systems use piped hot water. One of the pleasures of being in Korea in winter is finding a literal hot spot to sit or lie on, since the heating is not perfectly even.