题目内容：

but 13% of them -roughly four a day- are serious enough to require a pilot to ...帮忙翻译下
fainting and dizziness are the most frequent complaints. but 13% of them -roughly four a day- are serious enough to require a pilot to change course

优质解答

昏迷和头晕是最常听到抱怨的问题,但是他们当中的13%,也就是差不多每天4个,都很严重,需要飞行员改变航程.