请问they have been able to do的时态是什么?been able to 和 be able to的区别是什么_英语解答

请问they have been able to do的时态是什么?been able to 和 be able to的区别是什么?

人气：339 ℃　时间：2020-08-20 01:54:14

解答

现在完成时 have been able to 是 be able to 的现在完成时