unsurmountable

But for most members of the panel, the combination of misconduct allegations and the uncertainties about how to interpret the data seemed to create an unsurmountable hurdle.

However, these newly discovered anatomical features that allowed whales to successfully communicate in the vast oceans also poses unsurmountable physiological limits for many baleen whales.

The Northern Ireland branch of the Royal College of Emergency Medicine said the pressures were "unsurmountable" and it was having a detrimental impact on patients.

The world has solved large environmental problems that seemed unsurmountable at the time.

If government politics bend, the price tag could still prove unsurmountable.