about twenty-five of the ninety-two natural elements are known to be essential to life. which four of these twenty-five elements make up approximately 96 percent of living matter?

Which is true of chemicals? a. things containing chemicals always cost a lot of money. b. chemicals are never dangerous. c. chemicals are in many substances in a home. d. chemicals are rarely found on earth.

How have the greenhouse gasses increased from the year 2000 to 2018

When a septic tank backs up a goes in to clean it out