Question 13 (3 points) question 13 unsaved if we we will reduce the production of carbon dioxide. question 13 options: decrease coal consumption increase oil consumption increase natural gas consumption decrease wind energy consumption question 14 (3 points) question 14 unsaved what is the purpose of the three r's in reference to resource management? question 14 options: to consume increasing amounts of natural resources to remove resources from homes to spread out landfill areas to conserve resources question 15 (3 points) question 15 unsaved which of the following best describes how all the galaxies exist in the universe? question 15 options: they form clusters that are light years away from other clusters. they are evenly distributed throughout the universe. they exist together with no empty space in between them. they spin within a few miles of each other. question 16 (3 points) question 16 unsaved what would life on earth be like if it was not tilted on its axis with respect to its orbit? question 16 options: all places would have the same climate. there would be no day and night. there would be no seasons. the seasons would be much shorter. question 17 (3 points) question 17 unsaved the inner planets are known as the terrestrial planets. what characteristics define them as the inner planets? question 17 options: large gas planets, have own system of moons, made mostly of helium and hydrogen smaller than outer planets, high density, made of rock and metal, solid surfaces they have the same characteristics as the outer planets. larger than outer planets, each planets has numerous moons, low density question 18 (3 points) if two masses are moved farther apart, what happens to the force of gravity? question 18 options: it fluctuates. it stays the same. it decreases. it increases. question 19 (3 points) which of the following characteristics do all of the outer planets have in common? question 19 options: they have liquid cores. they are mostly made up of hydrogen and helium. they are small and dense. they lack moons.