In many or most animals, females are larger than males. most animals are insects and in many insects, females tend to be much larger than males because they are under strong selection for producing large numbers of eggs, and larger females can produce more eggs. is this an example of sexual selection?

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.