选A 好些,但这是道高考争议题,B也没错,你查牛津确认一下!我要原因不是答案阿= =答案是A比较繁琐的一个问题，现在有事要走了！ 以后再回答你了，不好意思！这个句子是as 引导的让步状语从句比如 Thoughhe is clever= Clever as he is Though he is a boy = Boy as he is (可数名词单数提前，要省略a/an)