at failing in the maths exam, John wouldn't like to talk about it to his parents.
A.Disappointing
B.Having disappointed
C.Disappointed
D.To be disappointed
答案:C
题目分析:考查非谓语动词。be disappointed at sth/doing sth因某事而感到失望,disappointed是形容词化的过去分词,类似的还有worried, interested, lost, absorbed等,根据句意可知,是发生过的事情,而不定式表将来,排除D,故选C。