1._many times,he finally understood it.A.Told B.Having been told2._time,the postman refused to deliver our letters unless we chained our dog.A Bitten B.Having bitten 还有第二题 如果用Having been bitten的话行么?什么时候用Having done什么的啊?这个不大会用 跟done也分不大清

1._many times,he finally understood it.
A.Told B.Having been told
2._time,the postman refused to deliver our letters unless we chained our dog.
A Bitten B.Having bitten
还有第二题 如果用Having been bitten的话行么?
什么时候用Having done什么的啊?这个不大会用 跟done也分不大清