On average, each American produces 4 pounds of trash each day (1,460 pounds of trash each year). To contain this trash, landfills are constructed. In what way do landfills primarily endanger ecosystems? A. They inhibit the recycling of materials, such as aluminum or paper. B. They could decrease the production of acid rain. C. They could contaminate surface and ground water sources. D. They encourage the rapid spread of infectious diseases.

8) animals respond in various ways to stimuli detected through their senses. some of these responses are stimulated by the presence of danger. which of these animal responses is the best example of a response to an immediate threat? a) a rooster crows every morning at the first sign of light. b) as something approaches an octopus, it shoots a cloud of ink. c) from late fall until spring, bears hibernate to preserve energy. d) a dog is getting hot in the sunlight, so he moves to a shaded area.