remain
to continue to be in the same state or condition
remain”强调状态的稳定性或延续性，后面可以接形容词，常接 “un”开头的形容词，比如unclear,unchanged,unanswered,unproven。
后也可以接名词，比如常见的有 a secret, an enigma：Whether the actor killed himself or was murdered remains a secret.=It remains unknown whether the actor killed himself or was murdered.
翻译：Mid-autumn festival remained to be one of the most celebrated festivals in China.
造句：1）Whether he can turn this table on remains to be seen in the following days.
2) The truth of Kennedy’s death remained unclear even after over 60 years.
