The system of the earth made up of all of the air on the planet is called the

Which of the following substances is not involved in the chemical reaction that pro- duces smog? a. sunlight b. particulate matter c. automotive exhaust d. ozone

Which of the following is the source of energy for photosynthesis? a.) glucose b.) chlorophyll c.) carbon dioxide d.) sunlight

Which feature of a human community is similar to a niche in a biological community