Which of the following is a secondary pollutant

Ais useful when you need a simple machine to you separate two things. a. lever b. screw c. pulley d. wedge

Aballet student who learns with the of his instructor is demonstrating learning.

Why is rain likely when warm, moisture-laden air meets cold air? a) the lighter warm air will rise and cool down, causing condensation and rain. b) the cold air moves faster and pushes the warm air away, causing condensation and rain. c) the moisture in the warm air condenses on contact with the cold air, causing rain to fall. d) the cold air mixes with the warm air, reducing its temperature causing moisture to condense.