<em>Answer:</em>
<em>4. The formation and evolutuion of stars and galaxies</em>
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Answer:
True.
Explanation:
The earth system is itself an integrated system, but it can be subdivided into four main components, sub-systems or spheres: the geosphere, atmosphere, hydrosphere and biosphere. These components are also systems in their own right and they are tightly interconnected.
Answer:
The correct answer is D. Umbilical cord
Explanation:
The umbilical cord connects the fetus to the placenta and through it exchanges nutritional substances as well as oxygen-rich blood. The umbilical cord is maintained throughout gestation until the moment of birth, when it is cut and leaves a permanent scar, the navel. The umbilical cord is responsible for breathing and feeding the fetus until the moment it is born, so any failure or blockage in the circulation of oxygen and nutrients through the cord can lead to injury or even death of the embryo. It also serves to remove waste and carbon dioxide (CO2).
Answer:
c.)natural
Explanation:
cotton, wool, and silk all grow themselves so they are natural
Without external and internal stimuli, your body would not be able to maintain homeostasis. Homeostasisis a property of systems that regulates their internal environment (blood levels, temperature, nutrient levels, etc.) and tends to maintain a stable, constant condition despite changing external conditions.
