According to the fossil record, which of the following types of organisms appeared on earth before the others? a) mammals b) insects c) fish d) land plants

Which statement best explains the difference between weather and climate

How do oceanographers measure the salinity of ocean water?

While viewing a topographic map, you notice a region in which the contour lines are very close together. what can you conclude about this region? a. it has a high population. b. it has a steep incline. c. it's near a political boundary. d. it contains a body of water.