A Alex New member May 15, 2009 #1 illustrated below, are composed of ___? a. gills and a two-chambered heart b. gills and a three-chambered heart c. gills and a four-chambered heart d. none of the above
illustrated below, are composed of ___? a. gills and a two-chambered heart b. gills and a three-chambered heart c. gills and a four-chambered heart d. none of the above