What groups of organisms are most in danger of extinction?
Which areas of the United States represent ecosystems with high levels of biodiversity?�
Lead poisoning and pesticides contributed to their decline. (choose the threat type & species it affects)
the introduction of hormones and thinning ozone layer (choose the threat type & species it affects)
Pacific coast fur trade (choose the threat type & species it affects)
commercial and housing development (choose the threat type & species it affects)