unclear

But it’s unclear whether venom is playing much of an active role.

It’s unclear where the word “Viking” came from, but in Old Norse it apparently referred to an act of maritime raiding.

But it’s unclear why this would happen in certain humans.

Prior to this level you have been unclear or, in the worst case, deliberately dishonest.

But since it’s unclear how any of these circadian changes could cause such significant shifts in mood, most researchers believe other factors are at play.

When exactly people began consuming coffee is unclear— but at some point before the 1400s, in what’s now Ethiopia, people began foraging for wild coffee in the forest undergrowth.

But Manet’s model, Victorine Meurent, portrays a sex worker— and perhaps was a sex worker in real life, though the historical record is unclear.