The film is very interesting .---students have seen it.A.a p

The film is very interesting .___students have seen it.A.a plenty of B.many of C.a great many如是A的话应该是A plenty of the students have....B的话应该是 Many of the students have...C是对的,A great many students have....为什么A plenty of 、 Many of 要 加 the