猜测英文短句

过去是我们定义，我们可以努力，有很好的理由去逃避，或去避免坏的事，但我们逃避它只是在上面添加一些美好而已。

有啊，这些词后面接have done就是过去含义。

有的；例如 Mr Smith must be at home now. He can't be from England (表状态) Mr Smith can't be having lunch now. It's only 10:30 (对现在动作的推测) Mr Smith couldn't have gone to the concert last night.(对过去动作的推测)