Why did identifying rock layers because of their fossils become important?
(a) it scientists determine the age of metamorphic rocks
(b) it allowed scientists to determine the age of strata
(c) it showed that layers are all different ages
(d) it was the first indication that the layers were from different ages

How many types of rock can form from the rock cycle

Which situation is an example of not doing work? lifting a couch throwing a baseball running up stairs carrying a box

1. in what ways have non-native species been beneficial? 2. what are some of the hypotheses for the collapse of honeybee colonies? 3. distinguish between regional and functional extinction. 4. why is it difficult to measure background extinction rates? 5. what three factors are most important in causing extinction rates to climb?