A type of trilobite is used as an index fossil. These fossils were made about 540 million years ago. A scientist finds a trilobite fossil in layer 3 in the
diagram below.

Melissa lives in a town called greendale. she discovers that when she lights a match and holds it near her kitchen faucet, the little flame grows into a larger fire. melissa is surprised because she thought the water would extinguish the flame rather than ignite it further. her mother tells her that the water might be contaminated with dissolved methane, a primary component in natural gas. melissa investigates the matter and finds that cases of methane contamination started shortly after a company began fracking for natural gas in the area. based on this information, which three statements are plausible consequences of fracking in greendale?

Which box will not accelerate? 4 newtons 4 newtons 4 newtons 25 kg 4 newtons 15 newtons 10 kg 30 newtons 40 newtons 50 kg 30 newtons 30 newtons

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.