Answer:
the correct answer is D
Explanation:
skin excretes sweat; lungs excrete carbon dioxide; kidneys excretes urine so these organs excrete metabolic waste because if you have learnt about the excretory system, you will come to know the process of excretion and how we humans excrete metabolic and toxic waste from the body.
Answer:
Scientists repeats the steps in cycle mode and in order to be sure about the results he/she chosen.
