50 years ago people were much more willing to get vaccines for diseases like polio, measles, and pertussis. Why are people more afraid to get them today?

Which plains area lies in both the united states and canada? altiplano central canadian shield coastal plains great plains

Give an example of a trait that is controlled by more than one gene.

Even though the ostrich is a flightless bird, ostriches still possess wings that stretch approximately two meters across when fully extended. scientists speculate that when dinosaurs became extinct, some of the birds that lived during that time became land dwellers since they were able to consume the food that the dinosaurs once ate. over time, these species grew larger and heavier. eventually, the ostrich species became too big to fly. the wings found on ostriches are known as a. analogous structures. b. homologous structures. c. vestigial structures. d. symmetrical structures.