Susan has selected exactly three crayons, each a different color, from a crayon box. How many crayon colors were represented in the box before her selection? 1. Exactly four distinct three-crayon color combinations were represented in the box before Susan selected three crayons. 2. Just before Susan`s selections, the box contained exactly five crayons. 这道题目答案是 c（both together） four distinct three-crayon color combinations 是什么意思？ 谢谢大家帮忙！ | 
