This is from Health class, please help ASAP.

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.

Many dental offices prefer preset trays because the use of these trays or what

Viruses can cause the following, check all that apply. a. sore throat b. measles c. ear infection d. flu e. chicken pox