对于那些没有单一证明文件的旅客，则必须出示身份证及公民证件。

Those travelers who do not have one of the single-document options must present both an identification document and a citizenship document.

youdao

对于那些没有单一证明文件的旅客，则必须出示身份证及公民证件。

Those travelers who do not have one of the single-document options must present both an identification document and a citizenship document.

youdao