Over-grazing is one of the most significant factor in environmental land degradation.
I know what you’re thinking – one means singular. Well, true, but that’s ‘over-grazing’ – even though it’s uncountable, the subject ‘over-grazing’ is a single thing. In this structure, one of + superlative adjective is telling us about ‘factors’, not about ‘over-grazing’. (more…)