Which component ot exercise primarily strengthens your heart

Blood cells bring oxygen to cells and take carbon dioxide away. true or false

0% 10. use the table to answer the question. which elements would you expect to find mainly in the earth’s core? element density (g/cm3) aluminum 2.7 iron 7.87 nickel 8.9 silicon 2.33 iron and silicon aluminum and silicon aluminum and nickel iron and nickel

Felicia has a respiratory infection and has been coughing up a lot of mucus. she knows this means that her respiratory system is working to restore balance by getting rid of the invasive materials from her lungs. how does this happen?