What is the ultimate source of energy for all ecosystems? OA. plants
OB. the Sun
OC. primary consumers
OD. secondary consumers

The united states produces an average of 429 billion pounds of food annually. about 133 billion pounds of that food ends up as waste. the percentage of food that the united states wastes each year is %.

The steps in the formation of extrusive igneous rocks are listed below in an incorrect order: 1. rock melts due to high temperature. 2. rock is buried deep under earth's surface. 3. magma is forced out of earth's surface during volcanic eruption. 4. lava cools and crystallizes to igneous rock. which of these best shows the correct order of steps in the formation of extrusive igneous rocks? 1, 3, 4, 2 2, 1, 3, 4 3, 4, 2, 1 4, 2, 1, 3

During convection, less dense fluid rises and denser fluid sinks.