(A)垂直和呈45°角 (B)水平和呈45°角 (C)垂直和水平 (D)水平和呈120°角
(A)無(wú)應(yīng)力 (B)無(wú)電磁干擾 (C)無(wú)振動(dòng) (D)無(wú)射頻干擾
(A)100m~1000m (B)100m~1500m (C)150m~1000m (D)150m~15000m