That is to say, if something happened -- and I've never seen anything like this happen, but I've only been looking for 20 years -- if something happened, they might all come out if they were needed.
也就是说，如果有事发生了---但我从来没有发现有这样的事发生， 但我也只关注了20年--- 如果有事发生，它们可以根据所需都会出去工作