Witch of the following accurately describes an example of how materials can move across the cell membrane through active transport

the speed increase from w to x due to increased gravity force

the speed decreases from x to y due to decrease in gravity

substitution is the answer in this case

your spelling is a little off : ]

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.