at the beginning of ne demek?

At the beginning of the 21st century, psychologists proposed that dreams create their own messages rather than displaying symbols of deeper feelings.YKSDİL 2026

The manipulation of genes resulted in hundreds of new products at the beginning of the 21st century. ---- The tools used by scientists in this process include DNA-splitting enzymes and host organisms including a range of bacteria.YDS 2021/1

If an age could ever be rightly described as ‘dark’ in European history, it ---- the two centuries that ---- the collapse of Roman authority in Britain at the beginning of the fifth century.YDS 2020/1

If the soldiers ---- at the beginning of the siege of Rhodes Island, they ---- to Crete or somewhere else with their treasures.YDS 2014/2