1 sentence

1. 在疫苗出现之前，很多传染病每年会夺去数百万人的性命。

   zài yì​miáo chū​xiàn zhī​qián, hěn​duō chuán​rǎn​bìng měi​nián huì duó qù shù​bǎi​wàn rén de xìng​mìng.

   Before vaccines existed, many infectious diseases killed millions of people per year.

   Source: CCMatrix