shì / chū / yǒu / yīn / yuán / lái / tā / zuó / tiān / shēng / bìng / le / cái / méi / lái / shàng / bān

事出有因，原来他昨天生病了才没来上班。

Everything happens for a reason — it turns out he was sick yesterday, so he didn't come to work.