【单选题】It was amazing that he knew nothing about the movie.
【单选题】倡导“相火论”,提出“阳常有余,阴常不足”的是
【简答题】已知等比数列{a n }中,a 2 ,a 3 ,a 4 分别是某等差数列的第5项、第3项、第2项,且 a 1 = 1 2 ,公比q≠1. (1)求数列{a n }的通项公式; (2)已知数列{b n }满足:a 1 b 1 +a 2 b 2 +…+a n b n =2n-1(n∈N * ),求数列{b n }的前n项和S n .
【单选题】What an amazing story he told us!
【单选题】It was amazing that he knew nothing.
【单选题】已知等比数列{an}中a1=1q=-2,则a=().