The answer is D, alters the test variable, and observes the effects on other outcome variables.
Outdoor pollution primarily results from the combustion of fossil fuels by industrial plants and vehicles. This releases carbon monoxide, sulfur dioxide, particulate matter, nitrogen oxides, hydrocarbons and other pollutants.
Answer:
Weather is the state in which a certain part inside the atmosphere is hot or cold.Climate is the usual weather in a certain place in the world or atmosphere.One way weather can affect climate is global warming,which is when the world gets hotter and the ice in the world melts and water rises.
Explanation:
These gases all have similar properties under standard conditions: they are all odorless, colorless, monatomic gases with very low chemical reactivity. The six noble gases that occur naturally are helium (He), Neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn).
I think it's false I'm just guessing
