1. Long ago, dinosaurs roamed the earth.
很久以前，恐龙在地球上漫游。

2. Long ago, people used to communicate through letters.
很久以前，人们通过信件进行交流。

3. Long ago, ancient civilizations built impressive structures.
很久以前，古代文明建造了令人印象深刻的建筑。

4. Long ago, our ancestors relied on hunting and gathering for survival.
很久以前，我们的祖先依靠狩猎和采集来生存。

5. Long ago, myths and legends were passed down through oral storytelling.
很久以前，神话和传说通过口头传统得以流传。

6. Long ago, traditional medicine was the primary form of healthcare.
很久以前，传统医学是主要的医疗方式。