Answer the following question given this paragraph: Because of human activities, there is more carbon dioxide in the atmosphere today than in the past hundreds of thousands of years. Burning fossil fuels and has released great quantities of carbon dioxide into the atmosphere. Cutting forests and clearing land has also increased carbon dioxide into the atmosphere because these activities reduce the number of autotrophic organisms that use up carbon dioxide in photosynthesis. In addition, clearing often involves burning, which releases carbon dioxide that was previously stored in autotrophs. Q: Cutting forests and clearing land has also increased the amount of what in the atmosphere? Choices: - oxygen - smog - pesticides - carbon dioxide A:
carbon dioxide

Answer the following question given this paragraph: Q: Physical and chemical differences help ecologists distinguish between freshwater and marine types of what? Choices: - cities - habitats - microbiomes - biomes A:
biomes

Answer the following question given this paragraph: Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We can't digest cellulose, but it helps keep food wastes moving through the digestive tract. Q: What is the most abundant biochemical compound, making up the cell walls of plants? Choices: - magnesium - cytoplasm - mitochondria - cellulose A:
cellulose

Answer the following question given this paragraph: The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. Q: The strength of bases is measured on what scale? Choices: - acid test - litmus test - pneumatic scale - ph scale A:
ph scale