must have done

Must have done 表对过去的推测.
Must have been done 表对过去的被动推测.
例句,She must have loved deeply,so she was so hurt.她一定曾经爱的深,才会如此受伤.
She must have been loved too,so she didn't have any regrets.她一定被爱过,所以她无憾.