题目

Which sentence is true? A . I have kept this book for two days. B . The movie had begun for twenty minutes. C . My uncle has away from his hometown since 10 years ago. D . Where have you gone these days? 答案：A若命题p的逆命题是q，命题p的否命题是r，则q是r的（　　 ） A．逆命题　   　B．否命题　   　C．逆否命题  　　   D．以上判断都不正确