HELP Which of the following are improvements in recent society that have lead to
decreased mortality rates? (Choose all that apply.)
medical care
sanitation
better schools
food production

Can you add a picture of the question?

The speed of  sound:   sound travels  at different speeds depending on what it istraveling through. of the three mediums (gas, liquid, and solid)  sound waves travel the slowest through  gases, faster  through  liquids, and fastest  through  solids.