yes,it is very useful to save a environment.
The environment is useful for animals as it is an animal's natural habitat. It's the same with humans.
it is useful because it can aware all the peoples to now about it and also to protect or environment to such harmful effects
Plant roots hold soil in place to prevent wind and water erosion.
Houseflies are quite useful to the environment as they help in decomposing of substances. They are also used as food by certain animals on earth.
an resource
Because it is freely available and it doesn't damage the environment.
ox, lizard,cow,...
changes both harmful and useful
Useful is the actual production of electricity. Non-useful -- unused heat energy released into the environment.
scratch paper
weird