At one point in history, all organisms were classified as either animals or plants. Which question could be asked in order to show the problems with
this type of model?
A. Can subsystems further classify the plants and animals?
B. How many types animals exist in the world?
C. How is an animal classified

D. Are bacteria considered plants or animals

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?