I think------he is not watching .
I don't think he is watching the football match (比较前面,可见,否定前移了,所以
I I don't think he is watching the football match,is he?
注：在i think/suppose 等后面接从句时,反意问句应该和从句中的主谓语保持对应关系
你的支持就是我的动力!