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.
The correct answer is B. After filtration, the lymph from lymph node travels to the subclavian veins, through efferent lymph vessels. The whole transport process is affected by smooth muscle contraction, changes in pressure and opening/closing of valves.
Answer:
yes
Explanation:
due to drift / variation human has been able to atttain high and advanced level of intelligence and development
Answer:
B. Native beetle species outcompete the nonnative species.
Explanation:
If native species outdoes the nonnative then the nonnative species cannot become invasive and take over the ecosystem.
