zhè / gè / shēng / dòng / de / bǐ / yù / gěi / zhěng / piān / wén / zhāng / qǐ / dào / le / diǎn / jīng / de / zuò / yòng这个生动的比喻给整篇文章起到了点睛的作用。This vivid metaphor added the finishing touch to the whole article.