“优先于”的英语可以翻译为：precede over，[经] take precedence of，have precedence over ...

她必须懂得，自己的愿望不能先于别人的需要。She had to learn that her wishes did not take precedence over other people's needs.对难分先后的冲线镜头的回放显示奥蒂先于奥运冠军到达终点。The replays of the close finish showed Ottey finished ahead of the Olympic champion...

“先于”的英语可以翻译为：[医]precede ...

“领先于”的英语可以翻译为：[体]lose ...

他在数学上领先于我.He is ahead of me in math.你略微领先于我.You have the edge on me....