Now the fourth most important crop worldwide after wheat, rice, and corn, potatoes are expected to supply even a larger share of the world's nutritional requirements in the next century if genetic engineering can increase its immunity to disease and expand its range of growing habitats.

answer: if she breaths she a thho

explanation:

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.