问题如下：
Following descriptions are regard to the binomial distribution, which one is most correct?
选项：
A.When we compute probabilities, the permutation formula is used.
B.The probability of zero in the binomial distribution may not be zero.
C.It is a continuous probability distribution.
解释：
B is correct.
If the random variable X is zero, it doesn't mean the probability of X must be zero.
二项分布不是n次的伯努利试验的结果么？为什么不是normal distribution？ 因为X取值范围不是负到正无穷？有点混淆了麻烦帮忙理清
