这座古老城堡的墙上有几处明显的退台设计。

The ancient castle's walls feature several noticeable ___setbacks in their design.

尽管遇到了一些挫折，他们仍然坚持完成了实验。

Despite several ___setbacks, they still persevered and completed the experiment.

尽管遭遇了一些挫折，他们仍然决心完成这个项目。

Despite several ___setbacks, they remain determined to finish the project.