The Medical and Science Technology advancement during the World War II played a significant role. These technologies were used to create better weapons for military use, such as the Atomic bomb that was first used during WWII. Medical and Science Technology was also for the advancement and innovation of chemical medicines and medical surgery.
Prior to the development of radio, the leader's speech is limited for the people who are physically present in the building or the field where the speech is given.
After the development of radio, the leader's speech could be heard from various places all over the nation.
