请简要分析该教师的行为体现了教学反馈的什么要求。
教学片段：
T：What’s the theme of the passage?Why do you think so?Student A，please．
A：The passage is about the invention of table tennis．
T：Good．Any other ideas?Student B．
B：It is about who invents the table tennis．
T：OK，sit down please．Anyone else?
(After a minute．)
T：OK．Who agrees with Student A?Please raise your hand．
(Some students raise their hand．)
T：Who agrees with Student B?
(Some other students raise their hand．)
T：Great．Now let’s read the passage again，and pay attention to the first sentence of each para graph．Let’s work out together whose opinion is the main idea of the passage，A’s or B’s．