Answer:
o2
Explanation:
Oxygen expelled by plants enters the air to be inhaled by animals and aerobic bacteria. Animal cells use oxygen for a process called oxidation.
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Trigone of the urinary bladder is made from three orifices, two <span>ureteric orifice and one urethra orifice.
Ureteric orifice is made by ureter from the left and right kidney. It's the place where urine enters the bladder.
Urethra orifice is connected to urethra and it's where the urine comes out of the bladder.</span>
Answer:
c.Endocrina
Explanation:
El sistema endocrino consta de órganos que producen sustancias químicas especiales llamadas hormonas.
Las hormonas son mensajeros químicos secretados directamente en el torrente sanguíneo que regulan diversas actividades en el cuerpo.
Por lo tanto, el sistema endocrino secreta sustancias químicas en el torrente sanguíneo.