lǎo / shī / yòng / jiè / chǐ / qīng / qīng / qiāo / le / qiāo / zhuō / zi / tí / xǐng / dà / jiā / ān / jìng

老师用戒尺轻轻敲了敲桌子，提醒大家安静。

The teacher tapped the desk lightly with the ruler to remind everyone to be quiet.