A:①②
B:②③
C:①④
D:③④
They arrived at a farmhouse, in front of ______ sat a small boy.
早晚空腹喝牛奶,不如喝牛奶时吃一些馒头等食品吸收率高,原因是前者被人体吸收的氨基酸主要被用于 ( )
我国处理民族关系的原则是( )