replacement

n. 交换,更换,代替者

The replacement of one image by another during a period of time by the motion of a boundary separating the visual parts of the two images.

在图象显示期间，一幅图象由另一幅图象取代。同一屏幕上，两幅图象的可见部分有一分界线，移动这一分界线，把一幅图象逐渐抹掉（划出），逐渐显示另一幅图象（划入）。

Good job they have get a replacement for him.

他们把他替换下来真不错。