4 sentences

1. 昔日的荒地如今已变成了繁华的商业区。

   xī​rì de huāng​dì rú​jīn yǐ biàn​chéng le fán​huá de shāng​yè​qū.

   The wasteland of the past has now turned into a bustling commercial area.

   Source: Dong Chinese Dictionary

2. 老同学聚在一起，共同重温昔日的校园生活。

   lǎo tóng​xué jù zài​yī​qǐ, gòng​tóng chóng​wēn xī​rì de xiào​yuán shēng​huó.

   Old classmates gathered together to reminisce about their school days.

   Source: Dong Chinese Dictionary

3. 经过多年的努力，昔日的荒山已经变成了果园。

   jīng​guò duō nián de nǔ​lì, xī​rì de huāng​shān yǐ​jīng biàn​chéng le guǒ​yuán.

   After years of hard work, the once barren mountain has been turned into an orchard.

   Source: Dong Chinese Dictionary

4. 这座历经沧桑的古城依然保留着昔日的光华。

   zhè zuò lì​jīng cāng​sāng de gǔ​chéng yī​rán bǎo​liú zhe xī​rì de guāng​huá.

   This ancient city, having weathered many changes, still retains its former glory.

   Source: Dong Chinese Dictionary