英语中has been silent里为什么会有been?

英语中has been silent里为什么会有been? 英语中have been；has been是什么? 英语：为什么填has been lisa's mother has been ill for two years.这个句子中为什么有been? He has been to the Great Wall中为什么been he has never been abroad是什么时态 为什么有been 英语句型-has been? there has been...为什么要加been? 英语,has been和 had been My brother has never been abroad before中为什么要用has never been 英语 完成时It has been raining for three hours.为什么要加been?加been不是表 He has been to the Great Wall中为什么用been