A new cinema---- here.they hope to finish it next month.a,has been built b,is being built

问题描述:

A new cinema---- here.they hope to finish it next month.a,has been built b,is being built
为什么不选a,has been built表示已经在建了,还没建完,意思对呀为什么不选

has been built表示已经建成了