List<List<string>> allList = new List<string>()
{
new List<string>(){"a","b","c"},
new List<string>(){"e","f","g"},
new List<string>(){"h","i","j"},
.......超过三行
}
求怎么获取 aeh,aei,aej,........ceh,cei,cej,cfh,....cgj