Differentiate between pre vist and field study​

How do the dry pampas and wet pampas contribute to the economic health of argentina

Jennifer is visiting her grandmother, who lives in the northeast corner of oklahoma. the region is home to many lakes, and jennifer enjoys canoeing on the illinois and grand rivers. to which region of oklahoma is she traveling? the prairie plains, the ozark plateau, the red river plains, the red beds plains

Some gamma ray bursts are hypothesized to come from mergers of neutron stars or black holes. if this hypothesis is correct, what else should we in principle be able to detect from such mergers? a. gravitiational waves b. x-ray bursts c. significant disruption of gas thousands of light-years away in the surrounding galaxy d. an "afterglow" of bright visible light, lasting for weeks