The answer is B. Geology has shown a thin layer of iridium (a rare mineral on earth but found on asteroids and meteors) in the rock layers between the Cretaceous and Paleogene periods. Below this layer are numerous fossils of pterosaurs and dinosaurs, but above the layer are drastically few. The aftermath of asteroid impact is believed to have smothered most vegetation from earth which dinosaurs depended on as a source of food.
<span>Sheet fractures are accurate fractures defining slabs of rock that range from 0.5 to 10 meters thick. They normally form in sets parallel to the Earth's surface but may form in convex-upward or concave-upward sets. The most popular hypothesis of the formation of sheet fractures is that they are the result of expansion and tangential fracturing consequent on erosion offloading or pressure release.</span>
The main difference is that quotas restrict quantity while tariff works through prices
