As you may recall from Unit 12, Energy Resources, coal is formed from decaying vegetation that is prevented from oxidizing in an anaerobic environment such as a swamp.
(you; may recall; from Unit 12) (coal; is formed; from decaying vegetation) (vegetation; is prevented; from oxidizing in an anaerobic environment such as a swamp)
you coal vegetation
may recall is formed is prevented
from Unit 12
from decaying vegetation
from oxidizing in an anaerobic environment such as a swamp