5. —Why didn't you come to the meeting?

D。the verb after have,has and had must be in past prefect form动词在have,has and had的后面要用过去分词的形式。over here have been / have not been is passive voice which mean that no one told he /she。在这里have been / have not been 是被动语态,意思是——我没有“被”任何人通知。