1. But the ratio is even greater among active women, affecting up to 80 percent of female endurance athletes.
    而这一比例在积极锻炼的妇女中数值更高，女耐力运动员中缺铁的则高达80%。

2. We divided it in the ratio of 3:1.
    我们按照三比一的比例将它分开。

3. For many years she has been puzzled as to why so many of the children in her study should be boys — at the top level, there are more boys than girls by a ratio of thirteen to one.
    多年来，她对为何她的研究中有那么多的男孩感到困惑 -- 高级组中男孩女孩之比为13比1。