tā / bǎ / zǔ / mǔ / liú / xià / de / yù / pèi / dàng / zuò / zuì / zhēn / guì / de / xìn / wù

他把祖母留下的玉佩当作最珍贵的信物。

He regards the jade pendant left by his grandmother as his most precious keepsake.