The ecol. system of the forest is carefully maintained to protect the wildlife.

The ecologist studied the behavior of the birds in their natural habitat.

The econ class focuses on studying economic theories and principles.

The United Nations imposed economic sanctions on the country to pressure them into changing their policies.

She studied economics in college.

I always try to economise by turning off lights when I leave a room.

The coral reef is a vital part of the ecosystem.

Political economy is a branch of social science that studies the relationships between individuals, society, and the economy.

I learned a lot about cooking and budgeting in my home economics class.

The new hybrid car has excellent fuel economy.