The Bering land bridge connected "<span>b. Asia and North America", since it was between what is now Russia and Alaska. This is how people originally migrated to the Americas. </span>
It led to recognition of post-traumatic stress as a legitimate psychological ailment
By exposing the citizen armies of Europe to prolonged and extreme
danger, World War One generated psychological casualties on an
industrial scale. This, in turn, created a military crisis that drew
doctors from a diverse range of specialties into the field of mental
health; never before had so much attention been focused on a single
psychiatric disorder.
The United States, Great Britain, France and Japan.
