A:rely o
B:rely on it
C:rely on that
D:rely on it that
4×2-4=____ 4×1=____
4×3+4=____ 4×4=____
抢救呼吸和心跳骤停的落水者时,需要采取心肺复苏的措施,为了提高抢救的成功率,心肺复苏措施的正确顺序是①开放气道②人工呼吸③胸外按压( )