Nature kills the weaker organisms and selects only the strongest organisms, which can survive and flourish. thats the right answer

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.

blue stars have the highest surface temp

stellar distances are usually expressed in light-years

the measure of a star's brightness is called magnitude

hope this !