tǎo / lùn / le / hěn / jiǔ / yǐ / hòu / wǒ / men / zhōng / yú / zhǎo / dào / le / zhè / ge / wèn / tí / de / yāo / yǎn

讨论了很久以后，我们终于找到了这个问题的腰眼。

After discussing it for a long time, we finally found the heart of the problem.