The exact functions of these higher areas are a matter of scientific research and debate.

The exact function and evolutionary history of these viruses are unknown.

The exact function of this matrix is still disputed, and its very existence has recently been called into question.

The exact function of this protein is not known, but it plays an important role in nerve cells.

Archaeologists have so far been unable to determine its exact function.

The exact function of these organs is not known.

Their exact function is unclear, as there are no written sources about them.

Not much is known about the exact function of these areas in the tip-of-the-tongue phenomenon.

With the judges were associated a body of elders who shared in the decision, but whose exact function is not yet clear.

The exact function of their product is not clear.