The book is ________. I wrote ________ name on its cover for ________.
A:my; my; myself
B:mine; my; myself
C:mine; myself; my
D:myself; mine; my
杜甫《登岳阳楼》“亲朋无一字,____”。
从前n个自然数中任取20个,其中必有两个数的差是5,则n的最大值为____ .