Ecology is a field of study that investigates the interrelationships of organisms in the natural world.

This substance undergoes a chemical change when heat is applied.

In this experiment, the substance will undergo a chemical change.

He is majoring in agronomy at university.

It's difficult to solve this formula.

This computer is using the latest technology.

He was able to solve the complex calculation quickly.

The Winter Triangle is a shape that connects the brightest stars in the night sky.

The Summer Triangle is shining in the night sky.

He drew a triangle on the blackboard.