Which of the following did not cause the reduction in sulfur dioxide emissions from sudbury's smelters? a) improving emission-control technology b) passing regulations requiring reductions in sulfur dioxide emissions c) permanently closing the nickel mines d) building the inco superstack

Layer r contains a well-known index fossil that is 100 million years old. based on this information and the principle of superposition, a. layers t and m are older than 100 million years, and layers x and g are younger than 100 million years. b. layers t, m, x, and g are all older than 100 million years. c. layers t and m are younger than 100 million years, and layers x and g are older than 100 million years.