A:①②③
B:②③④
C:①③④
D:①②④
Have you ____ (消化)everything that is important in the book.
已知角α的顶点与原点重合,始边与x轴的正半轴重合,终边经过点P(﹣3,m),且sinα=﹣45,则tanα等于( )
Jenny's teeth are not good, because she ____.
1858年,我师战败签订《天津条约》后,憎格林沁在大沽口伏击前来换约的人马,把对方打得人仰马翻,当英发派员前来谈判时,又活捉对方三十九人,并虐杀俘虏二十名,招致夷狄一怒之下进攻京师报复……“报复”指的是( )