Which option describes Darwin’s theory of natural sections?
Select all that apply

1. Natural selection results in descent with modifications
2.Evolution occurs because of natural selection
3. Natural selection occurs because of evolution
4.Natural selection results in populations staying the same over time

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.

geologic time scale (for gradpoint) =)

characteristics of hydrocarbons