Star is a brilliantly glowing sphere of hot gas whose energyis produced by an internalnuclear fusion process. Stars are contained in galaxies. A galaxy contains not only stars, but clouds of gas and dust. These clouds are callednebulae, and it is in a nebula where stars are born. In the nebula is hydrogen gas which is pulled together by gravityand starts to spin faster. Over millions of years, more hydrogen gas is pulled into the spinning cloud. The collisions which occur between the hydrogen atoms starts to heat the gas in the cloud. Once the temperature reaches 15,000,000 degrees Celsius, nuclear fusion takes place in the center, or core, of the cloud. The tremendous heat given off by the nuclear fusion process causes the gas to glow creating a protostar. This is the first step in the evolution of a star. The glowing protostar continues to accumulate mass. The amount of mass it can accumulate is determined by the amount ofmatter available in the nebula. Once its mass is stabilized, the star is known as a main sequence star. The new star will continue to glow for millions or even billions of years. As it glows, hydrogen is converted into helium in the core by nuclear fusion. The core starts to become unstable and it starts to contract. The outer shell of the star, which is still mostly hydrogen, starts to expand. As it expands, it cools and starts to glow red. The star has now reached the red giant phase. It is red because it is cooler than the protostar phase and it is a giant because the outer shell has expanded outward. All stars evolve the same way up to the red giant phase. The amount of mass a star has determines which of the following life cycle paths the star will take.
i believe the answer is d. hope it helps
Answer:
The correct answer is: mutualism
Explanation:
Mutualism refers to a relationship between two organisms, where both organisms benefit from the association. In this instance, the relationship between cellulose-digesting microorganisms and their hosts- termites and ruminant mammals- is characterized by mutualism because both organism benefit from their association. The microorganisms benefit by getting their nutrition from the cellulose in guts of their hosts. Whereas, the hosts benefit from the cellulose-digesting microorganisms by getting help in digesting the cellulose they consume in their diet.
Answer: a small body of matter from outer space that enters the earth's atmosphere, becoming incandescent as a result of friction and appearing as a streak of light.
Explanation:
Turbined water draining <span>transmission to consumers</span>
overhead connection
network connection
<span>voltage decrease </span><span>high-tension electricity transmission</span> <span>head of water </span><span>water under pressure </span><span>transformation of mechanical work into electricity </span>
generator unit
<span>transmission of the rotative movement to the rotor </span><span>rotation of turbine</span>
hydraulic turbine
<span>production of electricity by the generator </span><span>energy integration </span><span>voltage increase </span><span>energy transmission </span>
