The aero engine hummed steadily as the airplane taxied to the runway.

The marine engine failed during the trip, forcing the crew to anchor near the cove.

Before the long trip, she checked the engine oil level and topped it up to the recommended mark.

Before finalizing the plans, she measured each line with the engineer's scale to ensure the drawing matched real-world dimensions.

The mechanic compared several engine oils before recommending the best one for my car.

The marine engines hummed steadily as the research vessel crossed the foggy inlet.

The research team tested several prototype aero engines to improve fuel efficiency.

The beaver is a classic example of an ecosystem engineer, because its dams alter water flow and create ponds that support diverse wildlife.

During the outdoor concert, the sound engineers adjusted the levels to prevent feedback.

Beavers are classic ecosystem engineers whose dams create wetlands that benefit many other species.