Having been done是现在分词的完成时的被动语态,用的时候常常会出现一个段时间状语。having been done强调动作发生在谓语动词表示的动作之前。Having been done一般强调被动的动作。 相关推荐: 高考英语知识点汇总 come on四种意思分别是 最新高考资讯、高考政策、考...
33.The population of many Alaskan cities has ___ doubled in the past three years. A)larger than B)as great as C)more than D)as many as 34.All that can be done ___. A)have been done B)have done C)has done D)has been done 35.A person beating a drum o...
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