A child in South Sudan studies in a school. Fewer than half of the school-age kids are in school in South Sudan, one of the world's poorest countries, which has also been plagued by war.
Sebastian Rich/UNICEF South Sudan
Disrepair — such as this floor in the gym of Noble Elementary-Middle School in Detroit — and other problems have prompted the teachers' "sickout" protests.
Courtesy of Detroit Federation of Teachers