NO.PZ2021062201000010
问题如下：
Which one of the following statements concerning chi-square and F-distributions is false?
选项：
A.They are both asymmetric distributions.
B.As their degrees of freedom increase, the shapes of their pdfs become more bell curve-like.
C.The domains of their pdfs are positive and negative numbers.
解释：
C is correct, since it is false. Both chi-square and F-distributions are bounded from below by zero, so the domains of their pdfs are restricted to positive numbers
这两个分布不都是不对称的吗
