保护敦煌石窟，必须先从掌握周围自然环境入手。

To protect the Dunhuang grottoes, one has to start with an understanding of the surroundings.

youdao

保护敦煌石窟，必须先从掌握周围自然环境入手。

To protect the Dunhuang grottoes, one has to start with an understanding of the surroundings.

youdao