Which is the best action to take if you are at home and hear a tornado warning

Aperson who doesn't have enough calcium in his or her diet is at risk for developing bones that are weak and break easily. this condition is known as  a.  osteoporosis.    b.  crohn's disease.    c.  celiac disease.    d.  hemophilia.

At school, there have been a lot of rumors going around about how certain sexually transmitted diseases are spread. which skill would be most valuable to you take the necessary steps to learn what you need to know to protect yourself? a. self-direction b. critical thinking c. problem solving d. effective communication       select the best answer from the choices provided.

True or false a fertilized cell divides many times to form an embryo