The driver waits for the vertical retrace period 驱动程序需要等待垂直回描周期。
2.
The driver waits for the vertical retrace period the runtime will beam trace to prevent tearing 驱动程序需要等待垂直回描周期（运行库将实施跟踪以防止脱节） 。
3.
No attempt is made to synchronize the copy with the vertical retrace period of the display adapter , so tearing effects may be observed 由于没有尝试使复制与显示适配器的垂直回描周期同步，因此，可能会看到图像撕裂效果。
