Role and Importance of Data in Public Health. Address the basic concepts, methods, and tools of public health data collection, use, and analysis and why evidence-based approaches are an essential part of public health practice.
Every language in the world-from English to Mandarin-evolved from a prehistoric 'mother tongue' first spoken in Africa tens of thousands of years ago, a new study reveals.
A first language (also native language, father tongue/mother tongue, arterial language, or L1) is a language that a person has been exposed to from birth or within the critical period. If there are multiple L1, the designation first language is used for the L1 spoken the best or the one that is the basis for sociolinguistic identity.