he is going to relax with friends once the exams are -------
he is going to relax with friends once the exams are --------and he has exciting plans for the summer holidays A.at the end B.by the end C.in the end d.at an end
选C 解析:A 应该没有 at the end 这样的搭配 B.by the end of 通常表示将来 ,到……快结束/末尾的时候 By the end of 2007,I will go to Hainan to spend my holiday.到2007年底的时候,我要去海南度假. C.in the end 结束;最后;终于