They also want to know why safety officials failed to activate some emergency signals.

他们还想知道安全官员未能启动一些紧急信号的原因。

You suffer from muscle cramps When your body does not get enough water, it sends out an emergency signal to protect the most important organs.

肌肉抽筋症状当身体没有摄取足够的水分，它会发出紧急信号来保护最重要的器官。