diào / chá / zhè / qǐ / shì / gù / shí / jì / zhě / jué / dìng / zhuī / gēn / qiú / yuán / zhǎo / chū / zhēn / zhèng / de / yuán / yīn

调查这起事故时，记者决定追根求源，找出真正的原因。

While investigating the accident, the reporter decided to get to the root of the matter and find the real cause.