增加的染色体组来自同一物种的多倍体为同源多倍体，而增加的染色体组来自不同物种的多倍体为（）。
参考答案：异源多倍体
与百亿位相邻的两个数位分别是（ ）位和（ ）位。
A portfolio manager is looking at an investment that has an expected annual return of 10% with a standard deviation of annual returns of 5%. Assuming the returns are approximately normally distributed, the probability that the return will exceed 20% in any given year is closest to:（）
A. 0.0%.
B. 4.56%.
C. 2.28%.
