question: Without particles, water vapor could not do what?
distractor3: evaporate
distractor1: dissipate
distractor2: dilute
correct_answer: condense
support: Air includes many tiny particles. The particulates may consist of dust, soil, salt, smoke, or ash. Some particulates pollute the air and may make it unhealthy to breathe. But having particles in the air is very important. Tiny particles are needed for water vapor to condense on. Without particles, water vapor could not condense. Then clouds could not form, and Earth would have no rain.