第21题: [单项选择]The idea of traveling forward into the future or back into the past has always fascinated science fiction writers. The " grandfather______" is the argument many people use to suggest that time travel is impossible. A. paradox B. paradigm C. paranoia D. paraphia 参考答案:A 答案解析:解析:句意:科幻小说作家们常着迷于穿梭于过去和未来的想法中,而许多人却会用“祖父悖论”来说明时间旅行是不可能的。paradox“悖论,自相矛盾的观点”;paradigm“范例”;paranoia“偏执狂”;paraphia是指神经病学里的“触觉倒错”。只有A符合句意,故为答案。