BENSON RIOBA DEEP in Tana River County, in southeastern Kenya, a group of pupils formed a circle around their teacher, jotting down notes as they listened to a Swahili diction lesson coming from the solar-powered radio sitting in their teacher's lap. The radio the children from Dida Ade primary school gathered around was one of hundreds distributed for free to the most vulnerable households in the semi-arid region east of Kenya's capital, Nairobi. The radios allow children without internet access or electricity at home to continue studying while schools are closed to slow the spread of COVID-19, in a project…