miàn / duì / zhè / ge / fù / zá / de / wèn / tí / wǒ / men / xū / yào / nài / xīn / xún / gēn / wèn / dǐ

面对这个复杂的问题，我们需要耐心询根问底。

Faced with this complicated problem, we need to investigate it patiently and thoroughly.