题型:选择题 在△ABC中,a,b,c分别为角A,B,C的对边,且cos2B+cosB+cos(A-C)=1,则( )A.a,b,c成等差数列B.a,b,c成等比数列C.a,c,b成等差数列D.a,c,b成等比数列 查看答案
题型:选择题 The first thing _____ my brother is going to do this afternoon is to write a letter.A.whichB.thatC.whyD.who 查看答案