系统崩溃导致了整个网络的灾难性故障。

The system ___meltdown caused a catastrophic failure of the entire network.

她在重要演讲前紧张得情绪崩溃，在洗手间哭了很久。

She had a complete ___meltdown in the bathroom before her big presentation, crying uncontrollably.

核电站工作人员必须防止堆芯熔毁事故的发生。

Nuclear plant workers must prevent a reactor ___melt-down from occurring.