3 sentences for 年代 (nián​dài — decade)

1. 在二十世纪五十年代，这里曾是一个行政专区。

   zài èr​shí shì​jì wǔ​shí nián​dài, zhè​lǐ céng shì yī gè xíng​zhèng zhuān​qū.

   In the 1950s, this was an administrative prefecture.

   Source: Dong Chinese Dictionary

2. 20世纪50年代末，中国农村普遍建立了人民公社。

   20 shì​jì50 nián​dài mò, Zhōng​guó nóng​cūn pǔ​biàn jiàn​lì le rén​mín​gōng​shè.

   In the late 1950s, people's communes were widely established in rural China.

   Source: Dong Chinese Dictionary

3. 莫斯科中山大学在20世纪20年代为中国革命培养了大批干部。

   Mò​sī​kē Zhōng​shān Dà​xué zài20 shì​jì20 nián​dài wèi Zhōng​guó gé​mìng péi​yǎng le dà​pī gàn​bù.

   Moscow Sun Yat-sen University trained a large number of cadres for the Chinese Revolution in the 1920s.

   Source: Dong Chinese Dictionary