Pathogenic Is

Q29: Fluorides are added to water to<br>A)kill viruses.<br>B)remove

Q30: The principal cations in hard water are

Q31: Acid rain results in the release of

Q32: The saltiness of the oceans is<br>A)decreasing slowly.<br>B)increasing

Q33: Lakes and streams with granite rock bottoms

Q35: The water cycle acts to purify water

Q36: The EPA drinking water standard for arsenic

Q37: Contaminated water supplies and lack of adequate

Q38: Volatile organic compounds (VOC)make up one category

Q39: The density of ice is greater than