Which of the following best supports the idea that the atmosphere of early earth contained no oxygen?

Which heredity condition causes a buildup of mucus in lungs and pancreas? a. cystic fibrosis b. heart disease c. huntington's disease d. sickle cell anemia

Overtime the pond slowly becomes more acidic due to the release of chemicals from a nearby factory. which of the organisms would most likely survive the change to their environment?

Based on her survey, which advertising mediums will work best to publicize leslie's in-store specials?