tā / men / yuē / dìng / wú / lùn / yù / dào / shén / me / kùn / nan / dōu / yào / hǎi / kū / shí / làn / bān / de / shǒu / hù / zhè / fèn / gǎn / qíng

他们约定无论遇到什么困难，都要海枯石烂般地守护这份感情。

They promised to protect their relationship forever, no matter what difficulties they faced.