OG的意思好像就是用have been这部分来强调过去事实 再一个为了保持时态一致吧 1)He appears to have been happy, but his sudden suicide indicates that he was not. 2) He appeared to be happy. But his sudden suicide indicates that he was not.
这是longman里对appear的解释:used to say how something seems, especially from what you know about it or from what you can see 从这个解释可以看出应该用一般现在时,是从你现在看的情况得出的结论 而为什么用appear to have been equipped,因为要在不定式中表达出事件发生的先后,所以要只能用用完成时态
这是longman里对appear的解释:used to say how something seems, especially from what you know about it or from what you can see 从这个解释可以看出应该用一般现在时,是从你现在看的情况得出的结论 而为什么用appear to have been equipped,因为要在不定式中表达出事件发生的先后,所以要只能用用完成时态