In addition, hypotheses and popular rumors exist about Stalin's real father.

- Do you know how many hypotheses exists about Unfortunate?

The exact reason of such behavior is unclear, and at least two hypothesis exist.

Several competing hypotheses exist trying to explain the cause of the disease:

Various hypotheses exist about the fish's ability to live within the anemone without being harmed.

It is not known to reproduce in the marine environment and several hypotheses exist as to its source.

Several hypotheses exist on the true nature of the flush.

Several hypotheses exist, but mutually exclusive tests are still lacking.

Alternative hypotheses usually exist, and have to be considered.

But this is not certain and other hypotheses exist.