【文章要点】讲 two types of stage play ： representation and interaction。然后用吃做例子：
1)在representation情况下，演员当观众不存在，假装吃东西。
2)在interaction情况下，演员邀请观众吃晚餐，观众成为戏的一部分。
参考答案：
The lecture tells us about two types of stage play ： representation and interaction. In the former one, audiences only observe，while actors will act like they do in real life, presenting sequence of events； in the latter one actors and audiences interact together. Then the professor goes on to explain that by taking eating for example When in representation，they eat real food to show the audience that they are eating ； when in interaction, they will invite some of spectators to come to the stage and ask about the smell of the food.