Who here uses hangouts

Maintaining a healthy weight allows the respiratory system to work more effectively because a. oxygen is being delivered more adequately. b. the heart does not have to pump as forcefully. c. the capillaries are constricted. d. the lung capacity allows for small amounts of air.

The cardiovascular system, which transports blood through the body, is a one-way system. select the best answer from the choices provided. t f

Why is sustainable agriculture so important?