yī / shēng / gào / sù / wǒ / men / niú / dòu / hé / tiān / huā / shì / liǎng / zhǒng / bù / tóng / de / jí / bìng

医生告诉我们，牛痘和天花是两种不同的疾病。

The doctor told us that cowpox and smallpox are two different diseases.