They can’t have been doing their homework ---doing是什么词性?have been_英语解答

They can’t have been doing their homework ---doing是什么词性?have been 在这里还是表现在完成时吗

人气：164 ℃　时间：2020-02-05 17:48:38

解答

doing是do的进行式哈,不是词
have been doing是完成进行时,意即：他们不可能现在还在忙着他们的作业

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