Which of the following are changes to the environment which can lead to the spread of infectious diseases?
1.) soil erosion
2.) habitat destruction
3.) creation of irrigation canals and dams
4.) all of the above

The majority of sulfur dioxide produced by industry comes from a. oil refineries. b. dry cleaners. c. chemical plants. d. coal-burning power plants.

Which of the following is the best definition for the process of photosynthesis? a.) plants digest sugars to make energy. b.) plants use oxygen and glucose to make carbon dioxide. c.) plants use sunlight and carbon dioxide to make sugars. d.) plants use sunlight to make chlorophyll and chloroplasts.

How does food concentration affect yeast activity