He commentates on basketball matches for television .

他在电视上给篮球比赛作实况解说员.

John commentates on football matches for television .

约翰为电视解说足球比赛。

The first part is an introduction which introduces the topic 's origin , commentates on the allied studies at home and abroad and states this article 's study method .

第一部分是绪论，主要介绍选题缘起，评述国内外相关研究情况，阐述本文研究方法。