Is melting butter a physical or chemical change

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

State officials are considering constructing a road through a forested wilderness area. this action will likely affect the forest ecosystem in various ways. part a: predict how the construction of a road could negatively affect plants and animals in that ecosystem. (3 points) part b: describe one way that the construction of a road could have a positive impact of the forest ecosystem. (1 point)

The large increase in atmospheric carbon dioxide in the last 50 years most likely comes from a. an increase in cellular respiration b. increased decomposition by bacteria c. an increase in the burning of fossil fuels d. an increase in photosynthesis