To understand classical texts, you must learn how to form and use active participles correctly.

Scientists monitor active volcanoes in the Pacific Ring of Fire to predict eruptions.

Geologists monitor active faults closely to assess the risk of future earthquakes.

During the seminar, the professor described how activated complexes briefly form at the top of the potential energy barrier.

Comparing activation energies across different catalysts helped us predict the reaction rates.

During finals week, the library and campus café turned into beehives of activity, with students studying in every corner and friends exchanging notes at long tables.

Many schools have implemented drills to prepare students and staff for the possibility of active shooters.

During the drill, officers practiced protocols for containing an active shooter in a crowded mall.

Active galaxies often outshine their host galaxies, making it challenging to study the surrounding stellar populations.

During our island tour, we admired the steaming slopes of several active volcanos looming over the coastline.