withteenswhospendmuchoftheirfreetimeinfrontofTVset...

问题详情：

      with teens who spend much of their free time in front of TV sets, those who are physically active often have better grades.

    A. Compared         B. To compare       C. Comparing        D. Having compared

【回答】

A

知识点：非谓语动词

题型：选择题