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In the image, layer a is the topmost layer. layer c contains fossils from the precambrian era. layer b contains dinosaur fossils, and layer a contains fossils of mammals. which two statements are supported by this evidence? 1. mammals lived before the precambrian era. 2. dinosaurs and mammals existed in the precambrian era. 3. dinosaurs evolved after precambrian organisms. 4. precambrian organisms evolved after dinosaurs. 5. precambrian organisms were the first life-forms to become fossilized, according to this sample.

These three organisms are interdependent on each other for their survival. what will happen if foxes are eliminated from the region? a. there will be more rabbits and less grass in the region. b. there will be more grass and fewer rabbits in the region. c. there will be fewer rabbits and less grass in the region. d. there will be more rabbits and more grass in the region.

Apopulation of bolts has a mean thickness of 20 millimeters, with a population standard deviation of .01 millimeters. give, in millimeters, a minimum and a maximum thickness that includes 68% of the population of bolts.