When comparing data between two different groups,
A. the middles of the data sets and the spreads around them should both be considered.
B. only the average values of the data sets should be considered.
C. the most frequently occurring values and the middle values should both be removed from the data sets.
D. only the highest and lowest values of the data sets should be considered.

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed