What does the "graying" of a population refer to?

Why is the improved education of girls so important, especially with regard to economics and health? what are the leading causes of death among teenage girls in africa and how are they tied to education?

Which search pattern would be best suited for a crime scene where many investigators are available to search a large area? a. spiral b. grid c. line d. zone

Can someone answer all these questions i need it done by tonight. once again