Englishfor English speakers
sustainability
—
noun
the property of being sustainable
of
Preposition
—
Made using.
It is a house of cards.
ecological
—
adjective
characterized by the interdependence of living organisms in an environment
an ecological disaster
—
adjective
of or relating to the science of ecology
ecological research
system
Noun
—
A group of things that work together; a way of doing something.
This coloured paper is part of my system for keeping lists of people.