What happens before a black hole comes into existence?

The creation of the trans-siberian railway allowed people to travel across russia. how could this railway impact russian culture?

If we review the changes in the landscape surrounding the great salt lake in utah we can see a change in topography. look at the area to the south of the lake. what change has occurred during the last twenty-nine years? a) erosion of the hills b) an increase in marshland c) flooding of the area and the development of wetlands d) deposition of sediments and an increase in elevation

In which direction does the moving force of air flow? a-from warm temperatures to cold temperatures b-to areas of high pressure to areas of low pressure c-east to west d-from high elevations to low elevations