How has social media significantly changed the number and strength of our weak ties?

Humans are the only animals capable of communication

The middle east has very limited fresh water sources in the form of rivers such as the nile, jordan, euphrates, and tigris rivers. however, these rivers are only located in a few countries. which country does not have one of these rivers within its borders?

Which statement is correct? the speed of the light ray is the same in air and medium a. the speed of the light ray is the same in air and medium b. medium a and medium b have different densities because light refracts at different angles. medium a and medium b have the same density because the light ray strikes both at the same angle.