A submarine starts to ascend from a depth of 400 feet below sea level. It takes 160 seconds for it to reach the surface of the ocean. The graph shows the rate at which the submarine ascends. Use the submarine graph to answer questions 1 to 5. Identify the x-intercept of the graph. Explain what it represents in the context of this scenario. (4 pts) Replace each question mark with the correct number and complete the sentence. ( ? , ? )