Once you have started the training you will not be allowed to leave, unless unforeseen circumstances arise.一旦开始接受训练，你就不能退出，除非出现意外情况。We want action before a fatality occurs.我们希望在出现意外死亡之前采取行动。Barring any unforeseen problems, we should finish on time.除非出现意外情况，我们应能按时完工。