D, the independent variable is what you are changing
To perform this test to check if gold is real, make a light, tiny scratch on the item using a small nail file. Choose a spot that is not noticeable if possible. Use a dropper to apply a small drop of nitric acid to the scratch. If there is no reaction, then the piece is probably made from real gold.
Answer: Wetlands, animal digestion, along with thermogenic sources such as oil and gas production.
Explanation:
Methane (CH4)
Methane comes from natural sources, such as wetlands and animal digestion, along with thermogenic sources, including oil and gas production. Natural gas is approximately 90% methane. Hope this helped!
Answer:
Estrogen
Explanation:
Estrogen are hormones that increase the development and maintenance of female characteristics in the human body. Estrogen is involved in the development of a range of health issues.
