Sentence examples for a third possibility exists from inspiring English sources

However, a third possibility exists that Psn regulates CBP through a mechanism that is currently unknown.

Finally, a third possibility exists: Gli3 processing and Gli2 inhibition could be sensitive to different levels of PKA activity.

A second possibility exists: that unlike WT cells, the mutant crypt cells fail to withdraw from the cell cycle to repair lethal damage.

A second possibility exists in that ATMIN regulates not only Dynll1 expression, but also expression of other loci; we have demonstrated downregulation of Ift88, Ift172, Ift140 and FoxJ1.

However, if we consider these three types of attitudes from another angle, viz. the interaction between the embedding attitude verbs and the embedded epistemic modals, we may ask whether a fourth typological possibility exists, as Table 1 shows: could there be a fourth class of attitude verbs, which allows epistemic necessity but not possibility modals in their complement clauses?

This approach exemplifies the widely accepted Euclidean reductio ad absurdum, for which a proposition that cannot be demonstrated as true proves that its contrary is instead true, since a third possibility does not exist (tertium non datur).

However, there exists a third possibility: that the wrist is susceptible to violence (or stress) from within.

A third possibility is that dark energy does not exist at all, in which case not just the future, but the whole carefully constructed jigsaw puzzle of cosmology, might be in doubt.

A third possibility is that some parts of metabolism might exist as "modules" that can be reused in different pathways and perform similar functions on different molecules.

But consider a third possibility.

However, here's a third possibility.