VOA慢速英语:Studies Link Girls' Sports to Gains in Life

1.A lot of Americans may be surprised to know that it was written without saying anything directly about sports.

be surprised to know某人知道某事感到很惊讶，可以换一种形式，用形式主语来表示：It's suprised for a lot of Americans to know……
 
without saying，without和现在分词连在一起做状语。

2.For each ten percentage point increase in sports participation, she found a one point increase in female college attendance.

这个句型用来表示两个因素之间的关系经常用到，For each ten percentage…… a one point increase

3.He compared obesity rates and physical activity levels of women who had been in high school before and after Title Nine took effect.

这个句子中进行对比的两者是before和after第九条实施之后。对比的内容是obesity rates and physical activity levels。

take effect生效, 奏效
 
The prescribed medicine failed to take effect.
医生开的药没有见效。

4. Still, she says, far more boys than girls join sports teams nearly forty years after Title Nine gave girls a chance to level the playing field.

Still表示转折，相当于however。far more多的多，far在这里修饰形容词的比较级more。