【简答题】It's
a long time since l enjoyed myself, This sentence means ________A. I enjoyed myself for a long time. B. I
haven' t enjoyed myself for a long time. C. I want to enjoyed myself. D. what a long time...
【单选题】When the truth of sentence (a) gurantees the truth of sentence (b), and the falsity of senten (b) guarantees the falsity of sentence (a), we can say that ________________.