根据句意，用首字母适当的形式填空。

1. It's cold now. please put on your s_______.

2. In summer Bill likes to wear s______, and Helen likes to wear skirt, too.

3. How ______ are the pants? It's 30 dollars.

4. You cant' run fast without a pair of s_______.

5. Do you know that old man with a black h_______ over there?

一组数据中最大值与最小值的差值称为极差，极差越大时最可能是（）

A.均数的代表性越好

B.变异度越小

C.各变量值离均值越近

D.数据越分散

E.数据越集中