2 sentences

1. 研究表明，吸烟量与肺癌发病率呈正相关。

   yán​jiū biǎo​míng, xī​yān liàng yǔ fèi'ái fā​bìng​lǜ chéng zhèng​xiāng​guān.

   Research shows that smoking volume is positively correlated with the incidence of lung cancer.

   Source: Dong Chinese Dictionary

2. 改善卫生条件能有效降低传染病的发病率。

   gǎi​shàn wèi​shēng tiáo​jiàn néng yǒu​xiào jiàng​dī chuán​rǎn​bìng de fā​bìng​lǜ.

   Improving hygiene conditions can effectively reduce the incidence of infectious diseases.

   Source: Dong Chinese Dictionary