remain = to continue to be in the same state or condition
翻譯：
中秋節一直是中國人最喜歡慶祝的節日之一。
The Mid-Autumn Festival remains one of the festivals that the Chinese enjoy celebrating the most.
造句：
Though seventeen years has passed, the September 11 attacks remain vivid in the memories of many Americans.
雖然 17 年過去了，911 事件仍然讓很多美國人記憶猶新。
Whoever killed him remains unknown.
究竟是誰殺的他仍然不得而知。
