zài / gǔ / dài / lǐ / yí / zhōng / chén / xià / cháng / yǐ / dùn / shǒu / biǎo / shì / jìng / yì在古代礼仪中,臣下常以顿首表示敬意。In ancient etiquette, subjects often kowtowed to show respect.