16. Which of the following substances are elements (check all that apply)? hydrogen
carbon dioxide
calcium
water
air

What best describes emerging scientific ideas

An area has a few days of low humidity, warm air temperature, and high air pressure. what kind of weather is this area experiencing? o fog o snow storms o sun

Hairs that clean dirt out of the air in your nasal passages are called: a. sinus b. trachea c. cilia d. mucus