An unlabeled hierarchical diagram of various astronomical bodies is shown below. the labels a, b, c, and d can be used to represent the milky way, earth, universe, sun, and solar system. part 1: which four astronomical bodies would you choose to represent the four labels in the diagram? part 2: which astronomical body, other than the ones given, could also represent the label d? explain all your work

before, trains worked using the steam engine. thus, it uses heat so it is crucial to apply heat balance. the steam engine absorbs energy during the stage of boiling water. so, this is the endothermic reaction. when the steam is used to work the piston, it has to release this energy through running the train. the excess energy is released as an exhaust to the chimney. this is the exothermic process because it releases energy to the surroundings.

what? are the statements?