The force of gravity is a major force that created the earth. As rocks and ice clumped together as they spun around the newly formed star (sun), the force of gravitational pull increased and attracted more debris (rocks and ice). The clumps of rocks, debris, and ice, therefore, grew into a planet.
Another is electromagnetic force. The spinning currents in the outer core of the earth create a dynamo effect that forms a magnetic field around the earth. This shields the earth from the solar storms of the sun hence protects life and the atmosphere.
Weak nuclear force is responsible for maintaining the heat of the earth’s interior which is critical for maintaining the dynamo effect of the outer core so the earth is protected by its magnetic field.
Receptors which provide animals with information from the external environment are located in ears, tongue, eyes, and the nose. These are all receptors that can be found in our sensory organs and provide us with feedback from our nearby environment and the stimuli on which we should be alerted towards.
I think the independent variable is the temperature, while the dependent variable is the size of the balloon. The factor that is held constant is the amount of air in the balloon. An identical balloon kept at the original temperature. Independent variable in an experiment is the variable that the experiment plans to change while the dependent variable is the variable whose value depends on the independent variable.
<span>There are no choices given, but the event was most likely a physical one that would have barred the squirrels from seeing each other. Squirrels are a social creature, and the event that would have separated the populace could have been anything from a large fire to an earthquake that separated the squirrels from each other.</span>
The five are costs, availability, safety, content, and byproducts of the fuels use. Hope I helped!