Tīng / dào / xià / kè / líng / jiù / shōu / shi / shū / bāo / jī / hū / chéng / le / tiáo / jiàn / fǎn / shè

听到下课铃就收拾书包，几乎成了条件反射。

Packing up as soon as the class bell rings has almost become a conditioned reflex.