The human cardiovascular system is considered closed because blank a blood continuously circulated in the body b blood provides nutrients to organs c blood collects oxygen from the lungs d there are no holes from blood to enter or leave the system

The embryos of a bird, a reptile, and a mammal are similar in appearance. how does comparing the physical appearance of embryos of different species support the theory of evolution? a. it shows that these organisms share a common ancestor. b. it provides evidence that these organisms eat the same foods.c. it shows that these organisms share the same habitat.d. it provides evidence that these organisms suffered a genetic mutation.