4 sentences

1. 麻疹常并发肺炎。

   má​zhěn cháng bìng​fā fèi​yán.

   Measles is often complicated by pneumonia.

   Source: Dong Chinese Dictionary

2. 该系统能有效处理高并发请求。

   gāi xì​tǒng néng yǒu​xiào chǔ​lǐ gāo bìng​fā qǐng​qiú.

   The system can effectively handle high-concurrency requests.

   Source: Dong Chinese Dictionary

3. 这种现象通常由多种因素并发导致。

   zhè zhǒng xiàn​xiàng tōng​cháng yóu duō zhǒng yīn​sù bìng​fā dǎo​zhì.

   This phenomenon is usually caused by multiple factors occurring simultaneously.

   Source: Dong Chinese Dictionary

4. 暴雨和强风并发，给这座城市带来了严重的交通压力。

   bào​yǔ hé qiáng​fēng bìng​fā, gěi zhè zuò chéng​shì dài​lái le yán​zhòng de jiāo​tōng yā​lì.

   The combination of heavy rain and strong winds has put severe pressure on the city's traffic.

   Source: Dong Chinese Dictionary