when the air is very dirty we usually say it is ______. The thing which pollutes the air and the soil is _____. We should protect _____. Ecological problems can be _____. A person who doesn't eat meat is _____. If you protect the environment you are _____. If we want to reuse things or materials we usually ____. If you love nature you are _____. Garbage that can be easily burned is _____. Garbage that can't be burned is _____.