According to the researchers, which human activity is MOST likely to be a contributing factor in global warming? A) Humans have added carbon dioxide to the atmosphere by burning fossil fuels. B) Humans have released vast quantities of chemicals that have created excess ozone in the upper atmosphere. C) Humans have changed the chemistry of the world's oceans by the use of phosphates and nitrogen-containing compounds. D) Humans have created acid rain by releasing sulfuric acids into the air in the exhaust from factories and power plants.

Monarch butterflies have brightly colored orange wings with black patterns on them, making them easily visible to birds that eat butterflies and moths, yet birds rarely eat the monarchs. likewise, the monarch caterpillars are brightly striped yellow and white and black, and they also are rarely eaten by birds, although some wasps will attack them and feed them to their young. what can be inferred from these observations? monarchs must threaten and attack birds, but not wasps. monarchs have a way of discouraging bird predation that does not involve hiding. monarchs’ wings are so colorful that most birds must find them difficult to eat. monarchs lay more eggs than other less conspicuous butterflies.