Which statements show the importance of clean air? Check all that apply. Air is a natural resource. Governments manage air pollution to provide clean air. Lungs naturally purify the air, so air pollution does not harm people. Ultrafine particles contribute to 17,000 deaths per year in the United States. Particles in the air cause health problems.

Explain the difference between each pair of concepts. a. frequency and relative frequency b. percentage and relative frequency a. select the correct choice below. a. frequency is the total number of observations in a data set. relative frequency is the number of times a particular distinct value occurs. b. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of a value to the total number of observations. c. frequency is the total number of observations in a data set. relative frequency is the ratio of the number of times a particular distinct value occurs to the frequency. d. frequency is the number of times a particular distinct value occurs. relative frequency is the ratio of the frequency of two different values.

This is for my 8th grade science class, i really don’t understand. can someone me? , lol.

Which changes would result in a decrease in the gravitational force btween two objects? check all that apply