La población humana ha crecido mucho, con lo que las aguas residuales de las ciudades que se vierten a los ríos llegan al mar generando graves problemas de contaminación. ¿Qué solución ha ideado el ser humano para evitar que estas aguas residuales lleguen al mar tal como se han vertido a los río?

he forelimbs below belong to four species that descended in a direct line from the ancestral mammal shown above. of the four descendants shown, which species most likely appeared earliest in evolutionary history?

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.

the correct answer is 2 and 4

one part of the electromagnetic spectrum that arrives on earth as solar radiation from the sun is the visible spectrum. wavelengths of the visible spectrum combine to form what we refer to as

answer - d) ultraviolet radiation.

violet /   380–450 nm / 668–789 thz

violet is number 1 in the chart of visible light.