Sterilization controls the microbial in this world
<span>They are not visible because the chromatin coils up,shortens,and thickens.</span>
<u>The outer core of the Earth is a liquid layer and it is mainly made up of the metals iron and nickel. </u>
<u>It's also made up of small amounts of other substances. </u>
<u>The outer core is responsible for Earth's magnetic field. </u>
<u>The outer core is the second layer of the Earth.</u>
The answer is D. The natural selection is a theory which illustrates the gradual process of evolution in the population due to the change of environment. The key point is the mutation (variation) exists in the population before the environment changing. For C, if the environment does not change, though the adaptation is useful to environment, it will not be selected. Because the organisms without the adaptation will not die.
