When a bird flies, its wings push air downward. As a result the air pushes back upward on the bird. Which law of motion most applies to the way the wings of a bird beat?

You want to test the hypothesis that smoking cigarettes increases the risk of lung cancer. in your experiment, you take 100 people of various ages and genders for each of your groups. one group smokes. the other group does not smoke. the group that does not smoke is called the group