这部电影的大部分特效都是在后期制作阶段添加的。

Most of the special effects were added during the ___postproduction stage of this film.

这部电影的后期制作花了三个月时间，主要是添加特效和调整色彩。

The ___postproduction of this film took three months, mainly for adding special effects and adjusting colors.