The male secretory structures that produce a fluid necessary for adequate sperm motility after ejaculation are called the:

seminal vesicles and prostate gland

seminal vesicles are a pair of gland located behind the bladder, over the prostate gland (a walnut-sized gland located between the bladder and the penis) and opposite the rectum. seminal vesicles and prostate gland produces a fluid which feeds the sperm and this fluid has clotting ability that makes the semen sticky. this makes sure that the semen clings inside the vagina for a long time to allow the sperm to travel to the egg with ease.

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.