The revolution was almost two years old, and already there was talk of an impending crisis. "Impending" means ABOUT TO HAPPEN.

The Madrid Protocol protected Antarctica from exploitation.

A carbon footprint is the total amount of greenhouse gases produced by individuals or other entities in a given time period.

Overfishing disrupts the sensitive food web on the Great Barrier Reef.

"Instead of being delighted, as her husband had hoped, she flung the invitation petulantly across the table, murmuring." The word petulantly mean grumpily.

C. 24 km/h is a measurement of velocity.

Biology is NOT one of history's sister disciplines.