Developed countries are facing challenges because their populations are
aging due to decreased death rates.
increasing due to higher birth rates.
losing a sense of economic stability.
competing for limited natural resources.

How many time zone are there on earth

Sam hated the long nights of winter! his mother called him in from playing so early: around 4: 30 pm! it is usually dark out when sam is eating supper. what letter represents the long nights where sam lives? a) a. b) b. c) c. d) d.

The first atomic explosion was detonated in the desert north of alamogordo, new mexico, on july 16, 1945. what percentage of the strontium-90 ( yr) originally produced by that explosion still remains as of july 16, 2016?