Answer:
A., Vision. Eyes contain two types of photoreceptors called rods and cones.
The correct answer is B.
There's no statically significant association between the exposure and the disease. The risk ratio does not follow the normal distribution, even it does not depend on sample size in comparison groups. The natural rr is approximately normally distributed and is used to produce confidence interval which is for the relative risk.
Answer: Natural selection is a process by which species of animals and plants that are best adapted to their environment survive and reproduce, while those that are less well adapted die out.
Explanation:
