+2.00DC×90°与-2.00DC×180°联合后得到（）A、+2.00DS／-2.00DC×90°B、+2.00DS／-4.00DC×180°C、+2.00DS／-4.00DC×90°D、-2.00DS／+2.00DC×90°E、-2.00DS／+4.00DC×180°
题目
+2.00DC×90°与-2.00DC×180°联合后得到（）
- A、+2.00DS／-2.00DC×90°
- B、+2.00DS／-4.00DC×180°
- C、+2.00DS／-4.00DC×90°
- D、-2.00DS／+2.00DC×90°
- E、-2.00DS／+4.00DC×180°