tóng / shì / bāng / tā / dǎ / yǎn / hù / miǎn / de / lǎo / bǎn / fā / xiàn / tā / chí / dào / le

同事帮他打掩护，免得老板发现他迟到了。

His colleague covered for him so that the boss would not notice he was late.