Classes______ ,the students left for home without delay.A.were over B.being over C.are over D.over为什么选B呢?书上同样有个例子说是being可以省略的.例：The football match (being）over,crowds of people poured out into the street.如果按这个例子,那么选D也是可以的啊,那这样这个选择题就不严谨了.我看的是北京人大英语三级红宝书第112页、113页.

Classes______ ,the students left for home without delay.A.were over B.being over C.are over D.over
为什么选B呢?书上同样有个例子说是being可以省略的.例：The football match (being）over,crowds of people poured out into the street.如果按这个例子,那么选D也是可以的啊,那这样这个选择题就不严谨了.我看的是北京人大英语三级红宝书第112页、113页.