1,A
2,D
3,C
4,B
+
1,C
2,D
3,B
4,A
+
GroupJoin(
marbles2,
item1 => item1.Number,
item2 => item2.Number,
(item1, group) => new { item1.Number, Group = group }
)
1
1,C
2
2,D
3
3,B
4
4,A