Here's my current favorite:
And how could it happen that in California —and even in San Francisco, one of the first locales of AIDS —F(HIV) among childbearing women is quite low (less than 2 per 1000) [30, 31] and remained unchanged during six successive years (1990–95) ? With so many high-risk males in the vicinity, why were so few women infected?Gee. Are there any ladies who have spent time in the vicinity of high-risk males in, say, the Castro district of San Francisco circa 1980-95 who can let us in on their secret as to how they managed to remain uninfected by these high-risk males? Even despite getting in their vicinity?
Demographic Characteristics of HIV: I. How Did HIV Spread?