My grandpa___for 3 years,.空中因该填什么?1Died has died has been dead was dead有什么区别?

用has been dead.
die是个短暂性动词,不能用作长期状态,这道题中是说我的爷爷----三年了,显然是指一个状态,所以应该用be dead.
又因为有for,所以应该用完成时.
所以选择has been dead