链条断裂了。

The ___chain is broken.

他用链条把门拴住了。

He used a ___chain to secure the door.

这家连锁超市在全国有超过200家分店。

This supermarket ___chain has over 200 branches across the country.

一系列错误导致了这次项目的失败。

A ___chain of mistakes led to the failure of this project.