Which terms refer to major subsystems of Earth's physical systems? Choose all answers that are correct.
lithosphere
hydrosphere
biosphere
ionosphere

The impact of a large asteroid comet with earth has been proposed to have caused the extinction of the dinosaurs. the impact site of this comet is in or near

This is a 2017 topographic map of puerto rico in the united states, and i'm sorry that people there have suffered such a disaster. i want to ask, what do the yellow dots and areas represent on this graph? and the blue area and the little blue circle, and the little blue sign that looks like a signal tower, what do they stand for?

Countries in this region are trying to achieve development. a. attainable c. sustainable b. suspendable d. intangible