How does comparing different sources you get a more balanced view of the subject

What caused the united states to side with britain during world war i?

Why do the soldiers board the grounded boat

The maps below show the middle east. which best explains how the green areas depicted in the image on the left are reflected in the population map on the right? populations are greater in fertile areas that are close to freshwater sources, which is why more people live near deserts. populations are greater in fertile areas that are close to freshwater sources, which is why more people live near oceans. populations are greater in fertile areas that are close to freshwater sources, which is why more people live near mountains. populations are greater in fertile areas that are close to freshwater sources, which is why more people live near rivers. plz hurry in test only have 34 mins left