They're all tall, they all have blond hair, and they all seem to have blue eyes, too.
他们都是高个子、金发、看起来也都是蓝眼睛。
Precautions of this sort are necessary, for it is impossible to foretell the exact nature of the difficulties which will confront the pot-holer.
作出这样的准备是必要的,因为无法预见到洞穴探险者究竟会遇到什么性质的困难。